Sudden dislocation of the knee occurs clinically when the patella becomes subluxed or completely dislocated after direct or indirect external forces are applied to the knee joint. The patient is instructed to slowly straighten the knee joint and use the palm of the hand to push the patella inward during the straightening process, which can gradually reset the patella. After the patella is completely reset, the knee joint should be fixed in the straightened position, and at the same time, topical ointment should be applied to the injured area to activate blood circulation and eliminate blood stasis, reduce swelling and pain, so that the injured joint capsule and ligaments can be recovered as soon as possible to avoid secondary displacement. In addition, the patient also needs to use local hot compress treatment, give physiotherapy instrument baking electricity, microwave instrument treatment, etc., all can make this disease as soon as possible to recover.