Epicondylitis of the humerus, also known as tennis elbow, is a common chronic, strain disorder of the elbow that occurs in patients who frequently engage in forearm rotation or wrist extension and flexion activities. The external epicondyle of the humerus has the radial carpal long and short extensors, the common finger extensors, the intrinsic extensors of the little finger and the ulnar carpal extensors attached to it. The primary function of these muscles is wrist extension and finger extension. The tendon fascia attached to the lateral epicondyle of the humerus is strained when these muscles extend the wrist and fingers. If the stress is exceeded, the common tendon of the extensor muscle will be damaged. The pathological manifestations include local congestion, edema, exudation, adhesions, partial tearing of the extensor digitorum communis tendon, calcification and aseptic necrosis; degeneration of the annular ligament of the radial head; bursitis of the deep surface of the extensor digitorum communis tendon; periostitis of the humeral epicondyle, synovitis or hyperplasia of the synovial folds of the humeral radial joint, strangulation of the subcutaneous neurovascular bundle and neuritis of the articular branch of the radial nerve. The main symptom is slow onset of pain at the lateral epicondyle of the humerus, which may radiate to the radial side of the forearm, wrist or upper arm. The pain may radiate from the radial side of the forearm, the wrist or the upper arm. The hand cannot hold heavy objects, especially when the elbow is flexed, but can lift heavy objects when the elbow is in the straightened position. Elbow movement is normal on examination. There is a limited hyperplastic bulge at the lateral epicondyle of the humerus. There is significant pressure pain at the lateral epicondyle of the humerus, the radial head or the brachio-radial joint. A positive extensor tendon pull test (Mills test) is performed by straightening the elbow, making a fist, flexing the wrist, and then rotating the forearm forward, i.e. severe pain in the lateral part of the elbow occurs. Most of the patients are suitable for non-surgical treatment, including pressure point hydrocortisone acetate or confirmatory suxamethasone A local injection, as long as the injection is accurate, the efficacy is very good, but it should be noted that people with diabetes, severe hypertension and heart disease are contraindications to local sealing. Physiotherapy and massage also have some effect. If the non-surgical treatment is ineffective or recurrent attacks affect the function of the elbow after healing, surgical treatment is feasible. There are many surgical methods, which can be applied according to the clinical manifestations and the site of pressure and pain: including release of the attachment point of the extensor generalis tendon, partial resection of the annular ligament, extension of the radial extensor carpi radialis short tendon, cut of the articular branch of the radial nerve, cut of the subcutaneous neurovascular bundle, and cut of the superficial fascial arch of the posterior rotator muscle and release of the deep branch of the radial nerve.