el-tooltip slot="content"插槽显示数据 

                     <el-tooltip effect="light" style="overflow: hidden">
                        <el-descriptions title="" :column="1" slot="content" v-loading="loading"
                                         element-loading-spinner="el-icon-loading">
                          <el-descriptions-item v-for="item in detailInfoItems" :key="item.key" :label="item.title"
                                                style="width: 120px!important;">
                            <div class="formatted-text" v-if="item.key=='session_condition'">{{ item.value }}</div>
                            <div class="formatt-text" v-else>{{ item.value }}</div>
                          </el-descriptions-item>
                        </el-descriptions>
                        <span style="color: #409eff" v-on:mouseenter="handleFeatureDetial(scope.row.id)">{{
                            scope.row['status_display']
                          }}</span>
                      </el-tooltip>

el-popover  trigger="hover"

  <el-popover width="500" trigger="hover" effect="light" style="overflow: hidden">
                        <el-descriptions title="" :column="1" v-loading="loading"
                                         element-loading-spinner="el-icon-loading">
                          <el-descriptions-item v-for="item in detailInfoItems" :key="item.key" :label="item.title"
                                                style="width: 120px!important;">
                            <div class="formatted-text" v-if="item.key=='session_condition'">{{ item.value }}</div>
                            <div class="formatt-text" v-else>{{ item.value }}</div>
                          </el-descriptions-item>
                        </el-descriptions>
                        <span slot="reference" style="color: #409eff" @mouseenter="handleFeatureDetial(scope.row.id)">{{
                            scope.row['status_display']
                          }}</span>
                      </el-popover>

.formatted-text {
  white-space: pre-line;
}

.formatt-text {
  word-wrap: break-word;
  word-break: break-all;
}