diff --git a/crm-opportunity/src/main/java/com/crm/opportunity/config/SchemeCardOwnerMigrationRunner.java b/crm-opportunity/src/main/java/com/crm/opportunity/config/SchemeCardOwnerMigrationRunner.java
index 5b8f70c..8655118 100644
--- a/crm-opportunity/src/main/java/com/crm/opportunity/config/SchemeCardOwnerMigrationRunner.java
+++ b/crm-opportunity/src/main/java/com/crm/opportunity/config/SchemeCardOwnerMigrationRunner.java
@@ -69,9 +69,12 @@ public class SchemeCardOwnerMigrationRunner implements CommandLineRunner {
                 log.info("[scheme-card-owner-migration] 存量方案卡回填商机归属 {} 行", backfilled);
                 // 放宽旧列为可空：实体已不映射 opp_id，新插卡不带该列——NOT NULL 会让 A3 新建卡
                 // 首次 INSERT 即失败（真实环境实测）。旧行值保留供审计，新行 NULL。
-                jdbcTemplate.execute("ALTER TABLE " + TABLE + " MODIFY COLUMN opp_id bigint NULL"
-                        + " COMMENT '（已废弃·owner 化解耦遗留）历史所属商机ID，新行恒 NULL'");
-                log.info("[scheme-card-owner-migration] 旧列 opp_id 已放宽为可空");
+                // 仅在列仍 NOT NULL 时执行（幂等：已放宽的库启动零 DDL，避免共享库反复 ALTER）
+                if (!columnNullable(conn, TABLE, "opp_id")) {
+                    jdbcTemplate.execute("ALTER TABLE " + TABLE + " MODIFY COLUMN opp_id bigint NULL"
+                            + " COMMENT '（已废弃·owner 化解耦遗留）历史所属商机ID，新行恒 NULL'");
+                    log.info("[scheme-card-owner-migration] 旧列 opp_id 已放宽为可空");
+                }
             }
 
             if (!indexExists(conn, TABLE, "uk_osc_owner_customer")) {
@@ -99,6 +102,13 @@ public class SchemeCardOwnerMigrationRunner implements CommandLineRunner {
         }
     }
 
+    private boolean columnNullable(Connection conn, String table, String column) throws SQLException {
+        DatabaseMetaData meta = conn.getMetaData();
+        try (ResultSet rs = meta.getColumns(null, null, table, column)) {
+            return rs.next() && "YES".equalsIgnoreCase(rs.getString("IS_NULLABLE"));
+        }
+    }
+
     private boolean indexExists(Connection conn, String table, String indexName) throws SQLException {
         DatabaseMetaData meta = conn.getMetaData();
         try (ResultSet rs = meta.getIndexInfo(null, null, table, false, false)) {