option = {
  ......
  tooltip: {
    trigger: 'axis',
    borderWidth: 0, // 去除数据提示框默认的边框
    axisPointer: {
      lineStyle: { // 设置hover时竖线样式
        color: {
          type: 'linear',
          x: 0,
          y: 0,
          x2: 0,
          y2: 1,
          colorStops: [
            {
              offset: 0,
              color: 'rgba(128,200,244,0)' // 0% 处的颜色
            },
            {
              offset: 1,
              color: 'rgba(128,200,244,1)' // 100% 处的颜色
            }
          ],
          global: false // 缺省为 false
        }
      }
    },
    backgroundColor: 'transparent',  // 去除数据提示框默认的背景
    formatter: (p) => { // 自定义数据提示框默认的样式 返回DOM结构
      let dom = `<div style="width: 100px;
	        height: 50px;;color:#fff;position: relative;">
          <svg style="position: absolute;top: 50%;
            left: 50%;
            transform: translateX(-50%) translateY(-50%);" class="svg" xmlns="http://www.w3.org/2000/svg" width="100" height="71" viewBox="0 0 84 55">
            <defs>
              <style>
                .cls-1 {
                  fill: #07172c;
                  fill-opacity: 0.8;
                  stroke: #a7d8ff;
                  stroke-linejoin: round;
                  stroke-opacity: 0.2;
                  stroke-width: 1px;
                  fill-rule: evenodd;
                }
              </style>
            </defs>
            <path id="矩形_419" data-name="矩形 419" class="cls-1" d="M266,595h74v50H266V624.046L261,620l5-3.984V595Z"
            transform="translate(-258.5 -592.5)" />
          </svg>
          <div style="padding: 4px 8px 4px 17px;display: flex;
            justify-content: center;
            align-items: center;
            flex-direction: column;position: relative;z-index: 1;">
              <div style="margin-bottom: 4px;width:100%;display:${
                p[0] ? 'block' : 'none'
              };justify-content:space-between;align-items:center;">
                <span style="font-size:14px;color:#fff;">${
                  p[0]
                    ? '日期：' +
                      (p[0].name.indexOf('0') == 0
                        ? p[0].name.slice(1)
                        : p[0].name)
                    : ''
                }</span><br>
                <span style="font-size:14px;color:#fff;">${
                  p[0] ? '数值：' + p[0].data : ''
                }</span>
              </div>
            </div>
          </div>`;
      return dom;
    }
  },
  ......
};

效果如下：