The symptoms of facial palsy include loss of frontal wrinkles, enlarged eye fissures, flattened nasolabial folds, drooping corners of the mouth, and skewed corners of the mouth to the key side when the teeth are exposed. When eating, food residues are often retained in the gap between the teeth and cheeks on the sick side, and saliva often flows down from that side. Diagnosis of drooping corners of the mouth caused by facial palsy: 1. Eyebrow raising movement: Check the motor function of frontal occipital muscle frontal belly. In severe patients, the forehead is flat, wrinkles generally disappear or become significantly lighter, and the outer side of the eyebrows droop significantly. 2, frown: check whether the frown muscle can move, the two sides of the brow movement amplitude is consistent. 3.Eye Closure: When closing the eyes, attention should be paid to the affected side of the mouth with or without lifting the corner of the mouth movement, whether the affected side can be closed tightly, and the degree of closure. 4.Shrugging nose: Observe whether there are wrinkles in the nasal pressure muscle and whether the amplitude of upper lip movement is the same on both sides. 5, show teeth: pay attention to observe the amplitude of movement of the corners of the mouth on both sides, whether the mouth cleft is deformed, the number and height of the upper and lower teeth exposed. 6.Noodle: Pay attention to observe whether the distance from both sides of the corners of the mouth to the middle of the person is the same, and whether the shape of the noodle is symmetrical. 7. Cheek puffing: mainly check the motor function of the orbicularis oris muscle.