使用line，宽度增大到所需要的宽度，设置下颜色+透明度就行

tooltip: {
      trigger: 'axis',
      //把阴影的层级往下降
      z:-15,
      axisPointer: {
        type: 'line',
        lineStyle: {
          color: 'rgba(150,150,150,0.3)',
          width: 44,
          type: 'solid',
        },
      },
},
series: [
        {
        type: 'bar',
        barWidth:20,//柱状宽度
        barGap:'20%',//坐标轴占比
        itemStyle: {//柱状图渐变
            color: new echarts.graphic.LinearGradient(0, 0, 0, 1, [
            { offset: 0, color: '#f5b78c' },
            { offset: 0.3, color: '#a3948b' },
            { offset: 0.5, color: '#838485' },
            { offset: 0.8, color: '#395064' },
            { offset: 1, color: '#273d4f' }
            ])
        },
        emphasis: { label: { show: true ,position:'top',color:'pink'} },//鼠标放上显示柱状图数据
        data:[200,1000,800,500,25,14,950]
        }
    ]