修改

src/components/custom/custom-table.vue

@@ -118,4 +118,7 @@ const changePage = (page = currentPage.value) => {
 .page {
   margin: 10px 0 0 0;
 }
+:deep(.el-table .el-table__body td .cell:empty::before) {
+  content: '---';
+}
 </style>