1. 尝试调整yaxis.min和yaxis.max的值：

options: {
  chart: {
    type: 'line'
  },
  series: [{
    name: 'sales',
    data: [30, 40, 35, 50, 49, 60, 70, 91, 125]
  }],
  xaxis: {
    categories: ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep']
  },
  yaxis: {
    min: 0,
    max: 150
  }
}

2. 尝试使用yaxis.forceNiceScale选项：

options: {
  chart: {
    type: 'line'
  },
  series: [{
    name: 'sales',
    data: [30, 40, 35, 50, 49, 60, 70, 91, 125]
  }],
  xaxis: {
    categories: ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep']
  },
  yaxis: {
    forceNiceScale: true
  }
}