Lung percussion is one of the important examination methods in physical examination of vision, touch, percussion and hearing, and the steps and methods are briefly described as follows: 1. Environment selection: The environment of the examination needs to be highly quiet so as not to affect the examination results; 2. Positioning: The patient can be in a semi-recumbent or horizontal position, with the clothes unbuttoned to fully expose the chest, and the examiner needs to stand on the right side of the patient; 3. When examining the anterior chest, start from the supraclavicular fossa, tap along the midclavicular line from top to bottom, from the inside to the outside, symmetrically from left to right, and compare the changes of percussion sounds at the same horizontal symmetrical part on both sides, and the same for the back. The lateral chest wall is percussed along the mid-axillary and posterior axillary lines, starting from the axillary fossa, and examined down to the rib margin. The examiner should place the middle finger of the left hand, flat against the rib space in the chest to be tapped, with the finger flat against the rib space, parallel to the rib cage, and gently tap the middle of the middle finger of the left hand with the right middle finger. Usually, one area is tapped several times in a row, and the tapping force should be equal. Pay attention to the clear sound of normal lung tissue, the solid sound of solid lung changes, the over-clear sound or excessive reverberation of emphysema, the bulging sound of pneumothorax, the turbid sound of lung occupancy or pleural effusion, etc. Based on the clear and turbid local percussion sounds, adopt the light percussion method or heavy percussion method respectively, and pay attention to the changes of percussion sounds in different areas. The size of the abnormal percussion sounds should be used to determine the size of the lesion and the amount of pleural fluid. If one wishes to percuss the lower border of the lung or the boundary between the lung and the heart, it is usually necessary to carefully search for the turbid boundary between the lung and the liver, the lung and the heart, and the lung and the spleen along the lower border and both sides of the lung, but it is somewhat difficult.