There are generally three reasons for the poor pronunciation of the flute (regardless of the playing technique): First, the flute itself is of poor quality and relatively rare. Second, the flute is too dry and moist, commonly known as making the flute thirsty. You can wash the inner tube of the flute with clean water and dry it a little. The third is the flute membrane problem, which may be too thick; Maybe the flute membrane is not attached properly, so it is better to apply garlic juice around the flute hole before attaching it. When pasting, gently wipe it with your thumb, so that the "wrinkle" direction of the film is perpendicular to the flute tube, achieving the effect of "wave", which is long and tactfully.