diff --git a/backend/app/models/models.py b/backend/app/models/models.py
index bacfb1d1..73448b94 100644
--- a/backend/app/models/models.py
+++ b/backend/app/models/models.py
@@ -855,6 +855,7 @@ class OaInstance(Base):
     initiator_user_id = Column(String(64), nullable=False, comment="发起人")
     initiator_dept_id = Column(String(64), nullable=True, comment="发起人部门")
     form_data_json = Column(Text, nullable=True, comment="表单数据 JSON")
+    initiator_select_json = Column(Text, nullable=True, comment="发起人自选 JSON {nodeId:[userId,...]}")
     status = Column(
         String(32),
         nullable=False,
diff --git a/docs/sql/patch_2026-07-23_oa_instance_initiator_select_json.sql b/docs/sql/patch_2026-07-23_oa_instance_initiator_select_json.sql
new file mode 100644
index 00000000..09d38f10
--- /dev/null
+++ b/docs/sql/patch_2026-07-23_oa_instance_initiator_select_json.sql
@@ -0,0 +1,4 @@
+-- OA 实例：按节点持久化发起人自选（nodeId -> userId[]）
+ALTER TABLE oa_instance
+  ADD COLUMN initiator_select_json TEXT NULL COMMENT '发起人自选 JSON {nodeId:[userId,...]}'
+  AFTER form_data_json;