If the swelling of the finger requires drainage, one side can be incised and drained or both sides can be incised and drained. Finger swelling may be caused by purulent dactylitis, onychomycosis or septic tenosynovitis, and should be incised and drained when the patient is in severe pain and swelling is obvious. 1. Purulent dactylitis: when the patient is judged to need incision and drainage, the purpose is to avoid the occurrence of phalangeal necrosis and osteomyelitis. Usually, longitudinal incision is made on the side of the terminal phalanx, the distal end is not more than 1/2 of the nail groove, and the proximal end is not more than the transverse stripe of the phalanx, separation and cutting off the subcutaneous fibrous strips, and smooth drainage; if the pus cavity is large, it is appropriate to make counter-oral drainage, and cut off the excess fat, and the dead bone fragments should be removed. 2. Nail groove inflammation: abscess formation should be incised and drained longitudinally along the nail groove. 3. Purulent tenosynovitis: the purpose of incision and drainage is to prevent necrosis of the affected tendon. Septic tenosynovitis can be incised and drained on one side of the swollen tendon sheath, or bilateral incision can be made to drain, the incision should avoid the transverse stripe of the finger so as not to damage the tendon and affect the activity of the affected finger. After surgery, the affected limb should be elevated and immobilized in the functional position.