diff --git a/.changeset/import-multivalue-reference-split.md b/.changeset/import-multivalue-reference-split.md
new file mode 100644
index 0000000000..8592624b9d
--- /dev/null
+++ b/.changeset/import-multivalue-reference-split.md
@@ -0,0 +1,29 @@
+---
+'@objectstack/rest': patch
+---
+
+fix(rest): split multi-value fields on import so `multiple: true` columns resolve per-token (#3063)
+
+The bulk-import coercion (`import-coerce.ts`) resolved a reference cell as a
+single value regardless of the field's `multiple` flag: a `multiple: true`
+lookup/user cell like `张焊工;李质检` was passed whole to name resolution and
+always failed with `no <object> matches "张焊工;李质检"`, so every multi-value
+association had to be back-filled by hand in the record UI after import.
+
+Coercion now mirrors objectql's `isMultiValueField` predicate. A field whose
+stored value is an array — an inherently-multi type (multiselect/checkboxes/tags)
+or a multi-capable type flagged `multiple: true` (per the spec: select, lookup,
+file, image; `radio` shares select's branch and `user` shares lookup's) — has
+its cell split on the export separator (`, ` / `;` / `、` / newline) and each
+token coerced individually:
+
+- **lookup / user (`multiple: true`)** — resolve each name token to an id, store
+  the id array; an unmatched/ambiguous token reports the **specific token**
+  (`no sys_user matches "查无此人"`) instead of the whole string.
+- **select / radio (`multiple: true`)** — match each token against the options,
+  store the option-value array.
+- **file / image (`multiple: true`)** — split into an id/url array.
+
+Single-value fields and the non-multi-capable reference types (master_detail /
+reference / tree) are unchanged — a stray `multiple: true` on them stays a
+single resolved value, matching the engine.
diff --git a/packages/rest/src/export-format.ts b/packages/rest/src/export-format.ts
index e649bb16d2..b60129d7ea 100644
--- a/packages/rest/src/export-format.ts
+++ b/packages/rest/src/export-format.ts
@@ -22,6 +22,8 @@ export interface ExportFieldMeta {
   reference?: string;
   /** Field on the referenced record to show as its label. */
   displayField?: string;
+  /** Field holds multiple values (an array), e.g. a `multiple: true` lookup. */
+  multiple?: boolean;
   // The following four drive the import path's required-field pre-check
   // (import-runner.ts). They mirror the engine's insert-time validation
   // (objectql record-validator.ts) so a dry run can predict a NOT NULL /
@@ -127,6 +129,7 @@ export function buildFieldMetaMap(schema: unknown): Map<string, ExportFieldMeta>
       options: Array.isArray(f.options) ? f.options : undefined,
       reference: typeof f.reference === 'string' ? f.reference : undefined,
       displayField: typeof f.displayField === 'string' ? f.displayField : undefined,
+      multiple: f.multiple === true,
       required: f.required === true,
       system: f.system === true,
       readonly: f.readonly === true,
diff --git a/packages/rest/src/import-coerce.test.ts b/packages/rest/src/import-coerce.test.ts
index 100bb99412..740af7c283 100644
--- a/packages/rest/src/import-coerce.test.ts
+++ b/packages/rest/src/import-coerce.test.ts
@@ -158,6 +158,93 @@ describe('coerceRow', () => {
     expect(none.errors[0]).toMatchObject({ field: 'owner', code: 'reference_not_found' });
   });
 
+  it('splits a multi-value lookup cell and resolves each token to an id', async () => {
+    const metaMap = meta({
+      members: { type: 'lookup', reference: 'sys_user', displayField: 'name', multiple: true },
+    });
+    const ids: Record<string, string> = { 张焊工: 'u1', 李质检: 'u2' };
+    const seen: string[] = [];
+    const resolveRef = async (_obj: string, display: string) => {
+      seen.push(display);
+      return ids[display];
+    };
+    // Semicolon-separated (issue's CSV) and comma-separated (export round-trip).
+    const semi = await coerceRow({ members: '张焊工;李质检' }, metaMap, { resolveRef });
+    expect(semi.errors).toEqual([]);
+    expect(semi.data).toEqual({ members: ['u1', 'u2'] });
+    const comma = await coerceRow({ members: '张焊工, 李质检' }, metaMap, { resolveRef });
+    expect(comma.data).toEqual({ members: ['u1', 'u2'] });
+    expect(seen).toEqual(['张焊工', '李质检', '张焊工', '李质检']);
+  });
+
+  it('names the specific unmatched token in a multi-value lookup', async () => {
+    const metaMap = meta({
+      members: { type: 'lookup', reference: 'sys_user', displayField: 'name', multiple: true },
+    });
+    const resolveRef = async (_obj: string, display: string) =>
+      display === '张焊工' ? 'u1' : undefined;
+    const { data, errors } = await coerceRow({ members: '张焊工;查无此人' }, metaMap, { resolveRef });
+    expect(data.members).toBeUndefined();
+    expect(errors[0]).toMatchObject({ field: 'members', code: 'reference_not_found' });
+    expect(errors[0].message).toContain('查无此人');
+    expect(errors[0].message).not.toContain('张焊工');
+  });
+
+  it('keeps raw multi-value lookup tokens when no resolver is supplied', async () => {
+    const metaMap = meta({
+      members: { type: 'lookup', reference: 'sys_user', multiple: true },
+    });
+    const { data } = await coerceRow({ members: 'u1;u2' }, metaMap, {});
+    expect(data).toEqual({ members: ['u1', 'u2'] });
+  });
+
+  it('splits a select flagged multiple:true into an array of option values', async () => {
+    const metaMap = meta({
+      skills: {
+        type: 'select', multiple: true,
+        options: [{ label: '焊接', value: 'weld' }, { label: '质检', value: 'qc' }],
+      },
+    });
+    const { data, errors } = await coerceRow({ skills: '焊接;质检' }, metaMap, {});
+    expect(errors).toEqual([]);
+    expect(data).toEqual({ skills: ['weld', 'qc'] });
+    // A single-value select (no multiple flag) still stores one scalar.
+    const single = meta({ s: { type: 'select', options: [{ label: '焊接', value: 'weld' }] } });
+    const one = await coerceRow({ s: '焊接' }, single, {});
+    expect(one.data).toEqual({ s: 'weld' });
+  });
+
+  it('names the specific unmatched token in a multiple:true select', async () => {
+    const metaMap = meta({
+      skills: { type: 'select', multiple: true, options: [{ label: '焊接', value: 'weld' }] },
+    });
+    const { errors } = await coerceRow({ skills: '焊接,搬砖' }, metaMap, {});
+    expect(errors[0]).toMatchObject({ field: 'skills', code: 'invalid_option' });
+    expect(errors[0].message).toContain('搬砖');
+    expect(errors[0].message).not.toContain('焊接');
+  });
+
+  it('splits a file/image flagged multiple:true into an array of ids/urls', async () => {
+    const metaMap = meta({ photos: { type: 'image', multiple: true } });
+    const { data } = await coerceRow({ photos: 'a.png;b.png' }, metaMap, {});
+    expect(data).toEqual({ photos: ['a.png', 'b.png'] });
+    // A single-value file passes through untouched.
+    const single = meta({ f: { type: 'file' } });
+    const one = await coerceRow({ f: 'a.png' }, single, {});
+    expect(one.data).toEqual({ f: 'a.png' });
+  });
+
+  it('ignores multiple:true on types the spec does not make multi (master_detail)', async () => {
+    // master_detail is not multi-capable per the spec — a stray multiple flag
+    // must not split it; it stays a single resolved reference (engine parity).
+    const metaMap = meta({
+      parent: { type: 'master_detail', reference: 'order', displayField: 'name', multiple: true },
+    });
+    const resolveRef = async (_obj: string, display: string) => (display === 'A;B' ? 'o1' : undefined);
+    const { data } = await coerceRow({ parent: 'A;B' }, metaMap, { resolveRef });
+    expect(data).toEqual({ parent: 'o1' });
+  });
+
   it('reports coercion errors per field instead of throwing', async () => {
     const metaMap = meta({ n: { type: 'number' }, b: { type: 'boolean' } });
     const { data, errors } = await coerceRow({ n: 'abc', b: 'maybe' }, metaMap, {});
diff --git a/packages/rest/src/import-coerce.ts b/packages/rest/src/import-coerce.ts
index 9682b7df38..0edf6660c6 100644
--- a/packages/rest/src/import-coerce.ts
+++ b/packages/rest/src/import-coerce.ts
@@ -20,6 +20,12 @@
  *   - select / radio                                → an option *value*
  *   - multiselect / checkboxes / tags               → an array of option values
  *   - lookup / master_detail / user / reference     → a record id (resolved async)
+ *   - file / image                                  → a file id / url (as-is)
+ *
+ * Any of the last four whose field is flagged `multiple: true` (per the spec,
+ * `multiple` applies to select / lookup / file / image; `radio`/`user` share
+ * their branch) instead store an **array** — the cell is split on the export
+ * separator and each token coerced individually. See `isMultiValueField`.
  *
  * Contract: when a field carries no usable metadata the value passes through
  * untouched, so an import stays byte-identical to the pre-coercion behaviour.
@@ -37,6 +43,31 @@ const MULTI_OPTION_TYPES = new Set(['multiselect', 'checkboxes', 'tags']);
 const NUMBER_TYPES = new Set(['number', 'currency', 'percent', 'rating', 'slider']);
 /** Boolean field types (store a real boolean). */
 const BOOL_TYPES = new Set(['boolean', 'toggle']);
+/** Attachment field types (store a file id / url, or an array when `multiple`). */
+const FILE_TYPES = new Set(['file', 'image']);
+
+/**
+ * Single-value field types that become an ARRAY when flagged `multiple: true`.
+ * Mirrors objectql `record-validator.ts` (`MULTI_CAPABLE_TYPES`): per the spec
+ * (`field.zod.ts`), `multiple` applies to select / lookup / file / image;
+ * `radio` shares the select branch and `user` is stored identically to `lookup`.
+ * master_detail / reference / tree are NOT multi-capable, so a stray
+ * `multiple: true` on them is ignored (they stay single — same as the engine).
+ */
+const MULTI_CAPABLE_TYPES = new Set(['select', 'radio', 'lookup', 'user', 'file', 'image']);
+
+/**
+ * Whether a field's stored value is an array — an inherently-multi type
+ * (multiselect / checkboxes / tags) or a multi-capable type flagged
+ * `multiple: true`. Kept in lock-step with the engine's `isMultiValueField`
+ * so a coerced cell has the SAME shape the engine will accept on insert.
+ */
+function isMultiValueField(meta: ExportFieldMeta | undefined): boolean {
+  const t = meta?.type;
+  if (!t) return false;
+  if (MULTI_OPTION_TYPES.has(t)) return true;
+  return MULTI_CAPABLE_TYPES.has(t) && meta?.multiple === true;
+}
 
 /**
  * Structured outcome of a reference lookup. `id` set → a single record matched.
@@ -279,7 +310,24 @@ export async function coerceFieldValue(
     return { value: d };
   }
 
-  if (OPTION_TYPES.has(t)) {
+  // select / radio / multiselect / checkboxes / tags — match the cell against
+  // the field's option list. Multi-valued when the type is inherently multi
+  // (multiselect/…) OR a select/radio is flagged `multiple: true`; split then
+  // and match each token, else match the whole cell as one option.
+  if (OPTION_TYPES.has(t) || MULTI_OPTION_TYPES.has(t)) {
+    if (isMultiValueField(meta)) {
+      const parts = splitMulti(raw);
+      const out: unknown[] = [];
+      for (const part of parts) {
+        const v = matchOption(part, meta?.options);
+        if (v === undefined) {
+          if (ctx.createMissingOptions) { out.push(part); continue; }
+          return { error: { field, code: 'invalid_option', message: `${field}: "${part}" is not a known option` } };
+        }
+        out.push(v);
+      }
+      return { value: out };
+    }
     const v = matchOption(raw, meta?.options);
     if (v === undefined) {
       if (ctx.createMissingOptions) return { value: String(raw).trim() };
@@ -288,21 +336,29 @@ export async function coerceFieldValue(
     return { value: v };
   }
 
-  if (MULTI_OPTION_TYPES.has(t)) {
-    const parts = splitMulti(raw);
-    const out: unknown[] = [];
-    for (const part of parts) {
-      const v = matchOption(part, meta?.options);
-      if (v === undefined) {
-        if (ctx.createMissingOptions) { out.push(part); continue; }
-        return { error: { field, code: 'invalid_option', message: `${field}: "${part}" is not a known option` } };
+  if (REFERENCE_TYPES.has(t)) {
+    // Multi-value reference (a `multiple: true` lookup / user): the cell holds
+    // several display names joined by the export separator (`, ` / `;`). Split
+    // first, then resolve each token; store an array of ids. Mirrors the
+    // multi-option branch above and the export path's `formatReference` join.
+    if (isMultiValueField(meta)) {
+      const tokens = splitMulti(raw);
+      // If we have no resolver / no target object, store the raw tokens and let
+      // referential integrity be enforced downstream.
+      if (!ctx.resolveRef || !meta.reference) return { value: tokens };
+      const out: unknown[] = [];
+      for (const token of tokens) {
+        const m = normalizeRefMatch(await ctx.resolveRef(meta.reference, token, meta));
+        if (m.ambiguous) {
+          return { error: { field, code: 'reference_ambiguous', message: `${field}: "${token}" matches more than one ${meta.reference} — use a unique value or the record id` } };
+        }
+        if (m.id === undefined) {
+          return { error: { field, code: 'reference_not_found', message: `${field}: no ${meta.reference} matches "${token}"` } };
+        }
+        out.push(m.id);
       }
-      out.push(v);
+      return { value: out };
     }
-    return { value: out };
-  }
-
-  if (REFERENCE_TYPES.has(t)) {
     const display = String(raw).trim();
     // If it already looks resolved (an id was pasted) or we have no resolver /
     // no target object, store the raw value and let referential integrity be
@@ -318,8 +374,17 @@ export async function coerceFieldValue(
     return { value: match.id };
   }
 
-  // Everything else (text, email, phone, json, html, file, …): pass through,
-  // trimming string cells so stray spreadsheet padding doesn't leak into storage.
+  // Attachment fields (file / image): the value is a file id / url the importer
+  // does not resolve. When `multiple: true` the cell holds several joined by the
+  // export separator — split into an array so the stored shape matches what the
+  // engine expects; a single-value attachment passes through untouched below.
+  if (FILE_TYPES.has(t) && isMultiValueField(meta)) {
+    return { value: splitMulti(raw) };
+  }
+
+  // Everything else (text, email, phone, json, html, single file, …): pass
+  // through, trimming string cells so stray spreadsheet padding doesn't leak
+  // into storage.
   return { value: trim && typeof raw === 'string' ? raw.trim() : raw };
 }
 
diff --git a/packages/rest/src/import-integration.test.ts b/packages/rest/src/import-integration.test.ts
index b16f4d4315..ce977e2f91 100644
--- a/packages/rest/src/import-integration.test.ts
+++ b/packages/rest/src/import-integration.test.ts
@@ -94,6 +94,11 @@ const TASK = {
     score: { name: 'score', type: 'number' as const, label: '分数' },
     due: { name: 'due', type: 'date' as const, label: '截止' },
     owner: { name: 'owner', type: 'lookup' as const, label: '负责人', reference: 'user', displayField: 'name' },
+    members: { name: 'members', type: 'lookup' as const, label: '成员', reference: 'user', displayField: 'name', multiple: true },
+    skills: {
+      name: 'skills', type: 'select' as const, label: '技能', multiple: true,
+      options: [{ label: '焊接', value: 'weld' }, { label: '质检', value: 'qc' }],
+    },
   },
 };
 
@@ -188,6 +193,41 @@ describe('import route — real engine + protocol integration', () => {
     expect(String(stored.due)).toContain('2026-06-30');
   });
 
+  it('splits a multi-value lookup cell and resolves every token to an id (issue #3063)', async () => {
+    // The cell holds several display names joined by `;` (issue's CSV). Before
+    // the fix the whole string was resolved as one reference and always failed.
+    const csv = ['ID,标题,成员', '1,结构一班,张三;李四'].join('\n');
+    const res = await call(route, {
+      format: 'csv', csv,
+      mapping: { ID: 'id', 标题: 'title', 成员: 'members' },
+    });
+    expect(res._json).toMatchObject({ total: 1, ok: 1, errors: 0, created: 1 });
+    const stored = await engine.findOne('task', { where: { id: '1' } });
+    expect(stored.members).toEqual(['u1', 'u2']);
+  });
+
+  it('splits a select flagged multiple:true into an option-value array on insert (issue #3063)', async () => {
+    const csv = ['ID,标题,技能', '1,焊工,焊接;质检'].join('\n');
+    const res = await call(route, {
+      format: 'csv', csv,
+      mapping: { ID: 'id', 标题: 'title', 技能: 'skills' },
+    });
+    expect(res._json).toMatchObject({ total: 1, ok: 1, errors: 0, created: 1 });
+    const stored = await engine.findOne('task', { where: { id: '1' } });
+    expect(stored.skills).toEqual(['weld', 'qc']);
+  });
+
+  it('names the specific unmatched token in a multi-value lookup (issue #3063)', async () => {
+    const res = await call(route, {
+      format: 'json',
+      rows: [{ id: 'a', title: 'x', members: '张三;查无此人' }],
+    });
+    const failed = res._json.results.find((r: any) => !r.ok);
+    expect(failed).toMatchObject({ field: 'members', code: 'reference_not_found' });
+    expect(failed.error).toContain('查无此人');
+    expect(failed.error).not.toContain('张三');
+  });
+
   it('resolves a lookup by email when displayField is not the match, and reports not-found', async () => {
     // Default candidate fields include email — resolve 李四 via email.
     const res = await call(route, {