Facial paralysis occurs when the muscles on half of the face are inflexible. Facial paralysis is caused by paralysis of the facial nerve, which innervates facial muscle movements, including the muscles of expression and mastication. If the patient has facial paralysis, it will lead to the loss of function of these muscles and impaired mobility, and the patient often feels that half of the face is stiff. On neurological examination, it can be found that the frontal lines on the focal side of the patient become shallow, the nasolabial groove becomes shallow or disappears, the corners of the mouth will be crooked to the opposite side when showing the teeth, and there is incomplete eyelid closure, which often reveals white sclera when the eyes are closed while the eyeballs are rolled up to the outside and above the eyeballs. When the patient eats, there are often food residues left between the buccal mucosa and teeth on the lesion side, and sometimes there is involuntary drooling. The cause of this condition is usually a viral infection or non-specific inflammation of the facial nerve caused by exposure to cold and wind, and early hormonal therapy combined with antiviral therapy is required.