So I put some other task in my code, the first one is a blink (by using m5.apx.setled and vtaskdelay), It worked too. Then I tested it with demos of benchmark, music and widgets. And blink task, lvgl and touch fuction were all normal.

Seems everything went well, I changed the blink task into serial.println sth per 1s. Then I tested those 3 demos again, I found that the serial task worked well, lvgl worked well, but the touch funtion didn't worked. The serial task is sending thing every seconds normally, but i cant move the screen by touching in those demos, lvgl is working cus in benchmark demo, every tests is going but i cant move the screen to see the marks at the end of the demo.

So I try change the task back to blink, the touch function again. Seems it's sth about serial affect the touch function? But i dont know why.
Part of my code:

Task of blink or serial:

void Taskblink( void *pvParameters )
{
for(;;)
{
M5.Axp.SetLed(1);
vTaskDelay(800);
M5.Axp.SetLed(0);
vTaskDelay(800);
// Serial.println("i'm good..");
// vTaskDelay(1000);
}
}

Task of lvglhandler:

void Tasklvglhandler( void pvParameters )
{
for(;;)
{
lv_timer_handler(); / let the GUI do its work */
vTaskDelay(5);
}
}

lvgl touchpad read recall
void my_touchpad_read( lv_indev_drv_t * indev_driver, lv_indev_data_t * data )
{
TouchPoint_t coordinate;
M5.Touch.getPressPoint();

if (!M5.Touch.ispressed()){
    data->state = LV_INDEV_STATE_REL;
} else {
    data->state = LV_INDEV_STATE_PR;
    /*Set the coordinates*/
    coordinate = M5.Touch.getPressPoint();
    data->point.x = coordinate.x;
    data->point.y = coordinate.y;
}

}

Thanks for helping.