diff --git a/backend-node/src/controllers/popProductionController.ts b/backend-node/src/controllers/popProductionController.ts
index fca4baf2..c75a7476 100644
--- a/backend-node/src/controllers/popProductionController.ts
+++ b/backend-node/src/controllers/popProductionController.ts
@@ -393,8 +393,7 @@ export const syncWorkInstructions = async (
            -- detail에 routing이 있는 경우 (다중 품목 지원)
            EXISTS (
              SELECT 1 FROM work_instruction_detail wid
-             WHERE wid.work_instruction_no = wi.work_instruction_no
-               AND wid.company_code = $1
+             WHERE wid.work_instruction_id = wi.id
                AND wid.routing_version_id IS NOT NULL
                AND CAST(COALESCE(NULLIF(wid.qty, ''), '0') AS numeric) > 0
                AND NOT EXISTS (
@@ -433,11 +432,11 @@ export const syncWorkInstructions = async (
 			const detailResult = await pool.query(
 				`SELECT wid.item_number, wid.routing_version_id, wid.qty
          FROM work_instruction_detail wid
-         WHERE wid.work_instruction_no = $1 AND wid.company_code = $2
+         WHERE wid.work_instruction_id = $1
            AND wid.routing_version_id IS NOT NULL
            AND CAST(COALESCE(NULLIF(wid.qty, ''), '0') AS numeric) > 0
          ORDER BY wid.created_date ASC`,
-				[wi.work_instruction_no, companyCode],
+				[wi.id],
 			);
 
 			const detailRows = detailResult.rows;
@@ -448,9 +447,9 @@ export const syncWorkInstructions = async (
 				const firstDetail = await pool.query(
 					`SELECT routing_version_id, qty, item_number
            FROM work_instruction_detail
-           WHERE work_instruction_no = $1 AND company_code = $2
+           WHERE work_instruction_id = $1
            LIMIT 1`,
-					[wi.work_instruction_no, companyCode],
+					[wi.id],
 				);
 				const wid = firstDetail.rows[0];
 				if (wid) {
diff --git a/backend-node/src/controllers/workInstructionController.ts b/backend-node/src/controllers/workInstructionController.ts
index 1de120a7..f37584d3 100644
--- a/backend-node/src/controllers/workInstructionController.ts
+++ b/backend-node/src/controllers/workInstructionController.ts
@@ -96,7 +96,7 @@ export async function getList(req: AuthenticatedRequest, res: Response) {
         COUNT(*) OVER (PARTITION BY wi.work_instruction_no) AS detail_count
       FROM work_instruction wi
       INNER JOIN work_instruction_detail d
-        ON d.work_instruction_no = wi.work_instruction_no AND d.company_code = wi.company_code
+        ON d.work_instruction_id = wi.id
       LEFT JOIN LATERAL (
         SELECT item_name, size, type FROM item_info
         WHERE item_number = d.item_number AND company_code = wi.company_code LIMIT 1
@@ -170,7 +170,7 @@ export async function save(req: AuthenticatedRequest, res: Response) {
           `UPDATE work_instruction SET status=$1, progress_status=$2, reason=$3, start_date=$4, end_date=$5, equipment_id=$6, work_team=$7, worker=$8, remark=$9, routing=$10, updated_date=NOW(), writer=$11 WHERE id=$12 AND company_code=$13`,
           [wiStatus||"일반", progressStatus||"", reason||"", startDate||"", endDate||"", equipmentId||"", workTeam||"", worker||"", remark||"", routingVersionId||null, userId, editId, companyCode]
         );
-        await client.query(`DELETE FROM work_instruction_detail WHERE work_instruction_no=$1 AND company_code=$2`, [wiNo, companyCode]);
+        await client.query(`DELETE FROM work_instruction_detail WHERE work_instruction_id=$1`, [wiId]);
       } else {
         try {
           const rule = await numberingRuleService.getNumberingRuleByColumn(companyCode, "work_instruction", "work_instruction_no");
@@ -190,8 +190,8 @@ export async function save(req: AuthenticatedRequest, res: Response) {
 
       for (const item of items) {
         await client.query(
-          `INSERT INTO work_instruction_detail (id,company_code,work_instruction_no,item_number,qty,remark,source_table,source_id,part_code,routing_version_id,created_date,writer) VALUES (gen_random_uuid()::text,$1,$2,$3,$4,$5,$6,$7,$8,$9,NOW(),$10)`,
-          [companyCode, wiNo, item.itemNumber||item.itemCode||"", item.qty||"0", item.remark||"", item.sourceTable||"", item.sourceId||"", item.partCode||item.itemNumber||item.itemCode||"", item.routing||null, userId]
+          `INSERT INTO work_instruction_detail (id,company_code,work_instruction_no,work_instruction_id,item_number,qty,remark,source_table,source_id,part_code,routing_version_id,created_date,writer) VALUES (gen_random_uuid()::text,$1,$2,$3,$4,$5,$6,$7,$8,$9,$10,NOW(),$11)`,
+          [companyCode, wiNo, wiId, item.itemNumber||item.itemCode||"", item.qty||"0", item.remark||"", item.sourceTable||"", item.sourceId||"", item.partCode||item.itemNumber||item.itemCode||"", item.routing||null, userId]
         );
       }
 
@@ -216,10 +216,8 @@ export async function remove(req: AuthenticatedRequest, res: Response) {
     const client = await pool.connect();
     try {
       await client.query("BEGIN");
-      const wiNos = await client.query(`SELECT work_instruction_no FROM work_instruction WHERE id=ANY($1) AND company_code=$2`, [ids, companyCode]);
-      for (const row of wiNos.rows) {
-        await client.query(`DELETE FROM work_instruction_detail WHERE work_instruction_no=$1 AND company_code=$2`, [row.work_instruction_no, companyCode]);
-      }
+      // 디테일 삭제 (id 기반)
+      await client.query(`DELETE FROM work_instruction_detail WHERE work_instruction_id=ANY($1)`, [ids]);
       const result = await client.query(`DELETE FROM work_instruction WHERE id=ANY($1) AND company_code=$2`, [ids, companyCode]);
       await client.query("COMMIT");
       return res.json({ success: true, deletedCount: result.rowCount });