效果如图：

测试代码，可以直接黏贴到echart测试页面中
https://echarts.apache.org/examples/zh/editor.html?c=line-simple

option = {
  xAxis: {
    type: 'value',
    data: [1, 2, 3, 4, 6, 8, 10]
  },
  yAxis: {
    type: 'value'
  },
  series: [
    {
      data: [5, 5, 5, null, 6, 6, 7],
              type: 'line',
        markLine: {
            symbol:'none',
            label: { 
													formatter:'均值',
													position: 'end' },
            data: [
              //配置线端起始点
              [
                {
                  coord: [2, 3]
                },
                {
                  coord: [5, 3]
                },
                {
                          label: { 
													formatter:'name00',
													position: 'end' }
                      }
              ],
              
              [
                {
                  coord: [5, 4]
                },
                {
                  coord: [6, 4]
                }
              ],

            ]
        }
    }
  ]
};