diff --git a/src/main/java/com/spring/modules/quote/service/impl/QuoteDetailBomTreeServiceImpl.java b/src/main/java/com/spring/modules/quote/service/impl/QuoteDetailBomTreeServiceImpl.java
index 9dbfd163..af34c25e 100644
--- a/src/main/java/com/spring/modules/quote/service/impl/QuoteDetailBomTreeServiceImpl.java
+++ b/src/main/java/com/spring/modules/quote/service/impl/QuoteDetailBomTreeServiceImpl.java
@@ -189,12 +189,18 @@ public class QuoteDetailBomTreeServiceImpl extends ServiceImpl<QuoteDetailBomTre
                 BomNodeData childNode = collectBomData(childDetail, -1L, level + 1, ifsConFactory);
                 if (childNode != null) {
                     nodeData.children.add(childNode);
+                    // 半成品：bomId 在写入阶段填充，先清零价格（IFS 并行阶段会覆盖）
+                    component.setBomFlag("Y");
+                    component.setUnitPrice(BigDecimal.ZERO);
+                    component.setActualPrice(BigDecimal.ZERO);
+                    component.setQuotePrice(BigDecimal.ZERO);
+                } else {
+                    // collectBomData 返回 null 说明该子物料在 PLM 中无可用 BOM 数据，
+                    // 必须降级为 "N"，否则该组件会占用 childIndex 槽位，
+                    // 导致后续真实半成品的 bomId 错位（bomId=null），进而使人工成本计算错误
+                    log.warn("[BOM_PROCESS] 半成品 {} 的 BOM 数据收集失败（collectBomData 返回 null），降级为普通采购件处理", component.getComponentPart());
+                    component.setBomFlag("N");
                 }
-                // 半成品：bomId 在写入阶段填充，先清零价格（IFS 并行阶段会覆盖）
-                component.setBomFlag("Y");
-                component.setUnitPrice(BigDecimal.ZERO);
-                component.setActualPrice(BigDecimal.ZERO);
-                component.setQuotePrice(BigDecimal.ZERO);
             } else {
                 component.setBomFlag("N");
             }