在table中加  :cell-style="columnStyle"

    <div class="xzysledgerTable"  style="width: 100%; overflow-x:scroll">
      <el-table v-loading="loading" border :data="xzysListAll" :cell-style="columnStyle"> 
        <el-table-column label="单位" align="center" prop="deptId" width="150px">
          <template slot-scope="scope">{{deptFxFormat(scope.row.deptId,deptFxOptions)}}</template>
        </el-table-column>
        <el-table-column label="案号" align="center" prop="reference" width="155px">
          <template slot-scope="scope">{{scope.row.reference}}</template>
        </el-table-column>
        <el-table-column label="是否经复议" align="center" prop="isJfy" width="150px">
          <template slot-scope="scope">{{scope.row.isJfy=='0'?dictFormat(scope.row.isJfy, isJfyOptions):(scope.row.fyjgName !=null && scope.row.fyjgName !=''?(dictFormat(scope.row.isJfy, isJfyOptions)+' '+scope.row.fyjgName):dictFormat(scope.row.isJfy, isJfyOptions))}}</template>
        </el-table-column>
        </el-table-column>
      </el-table>
    </div>

methods中加方法

//row, 每一行上的数据

//column, 每一列上的数据

//rowIndex, 行数的下标从0开始

//columnIndex 列数下标从0开始

	  columnStyle({ row, column, rowIndex, columnIndex }) {
      //第一列的背景色
	    if (columnIndex == 0) {
            return "background:#F0F0F0";
	    }
	 },