解决方案：
在表格上添加了style="height: px;"和:max-height=""，这两个设置共同作用使表格在内容超过 设定高度时显示滚动条配合css使用
高度值可根据实际需求调整
<el-table:data="biddData"style="width: 100%; margin-top: 10px; height: 900px;"
row-key="id"
:border="false"
lazy
:tree-props="{children: 'children', hasChildren: 'hasChildren'}"
class="horizontal-line-table table-scroll"
:header-cell-style="{background:'#42b983', color: '#ffffff'}"
@selection-change="handleSelectionChange"
ref="multipleTable"
:max-height="900">
<el-table-columntype="selection"align="center"width="50">
</el-table-column>
<el-table-columnprop="mlname"label="名称"width="300"><template slot-scope="scope"><el-buttonv-if="scope.row.filecode === '1'"type="text"@click="handleClick(scope.row)">{{ scope.row.mlname }}</el-button><span v-else>{{ scope.row.mlname }}</span></template>
</el-table-column>
<el-table-columnprop="filetype"align="center"label="文件分类">
</el-table-column>
<el-table-columnprop="createtime"align="center"label="上传日期">
</el-table-column>
</el-table>
/* 表格滚动样式 */
.table-scroll {.el-table__body-wrapper {overflow-y: auto; /* 垂直滚动 */max-height: 900px; /* 与表格max-height保持一致 *//* 滚动条美化 (可选) */&::-webkit-scrollbar {width: 6px;}&::-webkit-scrollbar-thumb {background-color: #ccc;border-radius: 3px;}&::-webkit-scrollbar-track {background-color: #f5f5f5;}}/* 处理树形表格展开图标对齐问题 */.el-table__expand-column {vertical-align: middle !important;}
}