问题：

解决方式：

<el-table-column label="操作" fixed="right" width="132" align="center"><template slot-scope="scope"><div v-if="scope.row._index != '合计'"><el-dropdown trigger="click" type="primary" style="margin-top:0px;"><div class="el-dropdown-link btn2-icon btn-small-round btn2-bg-blue" type="primary">在线预览<i class="btnicon-more"></i></div><el-dropdown-menu slot="dropdown"><!-- <el-dropdown-item @click.native="onlineView(scope.row,'KHXX')">客户信息表</el-dropdown-item> --><el-dropdown-item @click.native="onlineView(scope.row,'SPDC')">审批调查表</el-dropdown-item><el-dropdown-item @click.native="onlineView(scope.row,'DCBG')">调查报告</el-dropdown-item></el-dropdown-menu></el-dropdown><el-dropdown trigger="click" type="primary" style="margin-top:0px;"><div class="el-dropdown-link btn2-icon btn-small-round btn2-bg-blue" type="primary">下载<i class="btnicon-more"></i></div><el-dropdown-menu slot="dropdown"><!-- <el-dropdown-item @click.native="downloadFile(scope.row,'KHXX')">客户信息表</el-dropdown-item> --><el-dropdown-item @click.native="downloadFile(scope.row,'SPDC')">审批调查表</el-dropdown-item><el-dropdown-item @click.native="downloadFile(scope.row,'DCBG')">调查报告</el-dropdown-item></el-dropdown-menu></el-dropdown></div></template></el-table-column>

给菜单单独添加样式进行修改

<style scoped>.btn2-icon i{display:inline-block; vertical-align:top; margin:2px 2px 0 0; width:20px; height:20px; }.btn2-icon i.btnicon-more{background:url(/static/img/feature/public/btn-icon-more.png) no-repeat center; background-size:20px;}.btn2-bg-blue, .btn-bg-blue:hover {width: 100px;margin-top: 4px;background-color: #62a8ea;color: #fff;}</style>

最后效果：