diff --git a/apps/server/src/modules/sources-identity/service/identity-admin.ts b/apps/server/src/modules/sources-identity/service/identity-admin.ts
index 441d8f6a..7b02c6ff 100644
--- a/apps/server/src/modules/sources-identity/service/identity-admin.ts
+++ b/apps/server/src/modules/sources-identity/service/identity-admin.ts
@@ -33,6 +33,7 @@ import { clearTmdbMetadata } from "./metadata.ts";
 import { metadataLanguages, metadataTextOptions } from "./metadata-rich.ts";
 import { recordAttempt } from "./resolve.ts";
 import { backfillRecognizeCache } from "./tmdb-recognize-cache.ts";
+import { mergeDuplicateUnits } from "./unit-merge.ts";
 
 // 人工纠错:指定来源资源身份(加锁)、改作品外部映射(新增修订、旧映射退役)、合并作品(旧 ID 跳转)。
 // 所有变更留 identity_revision / resolution_attempt / audit_event,不直接覆盖历史。
@@ -314,6 +315,15 @@ export async function setEntityIdentity(rt: SourcesRuntime, entityId: string, in
         .execute();
       for (const o of derived) await retireIdentity(trx, o, actor, "tmdb_mapping_changed");
       await clearTmdbMetadata(trx, id, rt.now());
+      // 旧 TMDB 条目带来的别名(没锁的)删除:留着会让旧作品的同名资源继续本地召回到这里;人工 / 站点别名保留,
+      // 刷新后按新详情重新登记 tmdb 别名
+      await trx
+        .deleteFrom("title_alias")
+        .where("media_entity_id", "=", id)
+        .where("content_unit_id", "is", null)
+        .where("source", "=", "tmdb")
+        .where("locked", "=", false)
+        .execute();
     }
     await audit(
       trx,
@@ -414,7 +424,7 @@ export async function updateExternalIdentity(
 
 /**
  * 合并重复作品:from → into。旧 ID 保留(status=merged + merged_into_id)并写 identity_redirect;
- * 本模块的引用(来源资源、别名、待识别池、外部身份)迁到目标;其它模块的表按 merged_into_id 跳转解析。
+ * 本模块的引用(来源资源、别名、待识别池、外部身份、内容单元)迁到目标;其它模块的表按 merged_into_id 跳转解析。
  */
 export async function mergeEntities(
   rt: SourcesRuntime,
@@ -483,6 +493,35 @@ export async function mergeEntities(
       select ${intoResolved}, null, alias, normalized, language, kind, source, locked from title_alias
        where media_entity_id = ${fromId} and content_unit_id is null
       on conflict (media_entity_id, content_unit_id, normalized, kind) do nothing`.execute(trx);
+    // 内容单元随作品迁到目标(M3):单元改归目标作品;与目标已有单元同季同集的
+    // 按重复单元合并(所有引用改指向保留的那条,见 unit-merge.ts)。目标是电影时源作品的单元退役
+    const into = await trx
+      .selectFrom("media_entity")
+      .select(["kind"])
+      .where("id", "=", intoResolved)
+      .executeTakeFirstOrThrow();
+    if (into.kind === "movie") {
+      await trx.updateTable("content_unit").set({ status: "retired" }).where("media_entity_id", "=", fromId).execute();
+    } else {
+      const moved = (
+        await trx
+          .updateTable("content_unit")
+          .set({ media_entity_id: intoResolved })
+          .where("media_entity_id", "=", fromId)
+          .returning(["id"])
+          .execute()
+      ).map((u) => u.id);
+      if (moved.length) {
+        // 单元级元数据 / 覆盖只挂 content_unit_id,随单元走;单元级别名还带作品 ID,一并改
+        await trx
+          .updateTable("title_alias")
+          .set({ media_entity_id: intoResolved })
+          .where("media_entity_id", "=", fromId)
+          .where("content_unit_id", "in", moved)
+          .execute();
+        await mergeDuplicateUnits(trx, intoResolved);
+      }
+    }
     await trx
       .updateTable("source_release")
       .set({ media_entity_id: intoResolved })