myChart.showLoading();
$.get('data/asset/data/flare.json', function (data) {
    myChart.hideLoading();

    echarts.util.each(data.children, function (datum, index) {
        index % 2 === 0 && (datum.collapsed = true);
    });

    data.children[0].itemStyle = {
        color : '#0000ff',
        borderColor:'#0000ff'
    };
    data.children[0].lineStyle = {
        color : '#0000ff',
        borderColor:'#0000ff'
    }

    myChart.setOption(option = {
        tooltip: {
            trigger: 'item',
            triggerOn: 'mousemove'
        },
        series: [
            {
                type: 'tree',

                data: [data],

                top: '1%',
                left: '7%',
                bottom: '1%',
                right: '20%',

                symbolSize: 7,

                label: {
                    normal: {
                        position: 'left',
                        verticalAlign: 'middle',
                        align: 'right',
                        fontSize: 9
                    }
                },

                leaves: {
                    label: {
                        normal: {
                            position: 'right',
                            verticalAlign: 'middle',
                            align: 'left'
                        }
                    }
                },

                expandAndCollapse: true,
                animationDuration: 550,
                animationDurationUpdate: 750
            },
            
        ]
    });
});

直接在data中设置lineStyle （树边样式），itemStyle（节点样式）。

 

代码可直接复制到官方例程中测试