select 属性配置：
v-model 绑定的是数组

              <el-select
                    v-model="selectedStocks"
                    multiple
                    filterable
                    remote
                    default-first-option
                    :reserve-keyword="false"
                    placeholder="股票代码/拼音"
                    loading-text="查询中..."
                    no-match-text="无匹配"
                    no-data-text="无"
                    style="width: 100%;"
                    value-key="id"
                    :multiple-limit="stockLimit"
                    :loading="isStockSearching"
                    :remote-method="searchStock"
                    @change="stockChange">
                    <el-option
                      v-for="item in stockTable"
                      :key="item.id"
                      :label="item.label"
                      :value="item">
                    </el-option>
                  </el-select>