这里的线条控制的是

      labelLine: {
        show: false
      },

一般而言我们可能需要加一个数字之类的

  series: [
                    {
                        name: '',
                        type: 'pie',
                        radius: ['40%', '70%'],
                        label: {
                            formatter: '{b|{b}：}{c}  {per|{d}%}  ',
                            rich: {
                                b: {
                                    color: '#6E7079',
                                    lineHeight: 22,
                                    align: 'center'
                                },
                            }
                        },
                        }
                        }