First, depending on the site of injury, the clinical manifestations of the injury are not exactly the same. Above the axilla, the beginning of the radial nerve injury, it is manifested as elbow extension, wrist extension, finger extension, thumb extension are unable. Loss of sensation in the radial side of the dorsum of the hand and the two half fingers of the radial side. However, simple radial nerve injury in the axilla is rare, often combined with other nerve injuries, should pay attention to the brachial plexus injury to distinguish. Second, injury in the upper arm, the elbow joint can be normal extension, but wrist extension, even, thumb function loss, skin sensory loss as above; elbow injury, no elbow extension movement disorder, wrist joint can also be actively extended, but finger extension, thumb function loss, skin sensory loss as above; injury below the elbow joint, the deep branch of the radial nerve injury, depending on the site of injury, can appear finger extension, thumb function loss or partial loss. Third, the treatment of radial nerve injury: closed injury, after 1 to 3 months of observation, no signs of recovery, should be surgical exploration. Open injury should be surgically explored as soon as possible. The choice of surgical approach, according to the site of injury, post-injury clinical manifestations, choose the site of surgical exploration. 1, upper arm mid-section exploration: upper arm lateral incision, can start from the midpoint of the posterior edge of the deltoid muscle, down to the midpoint of the upper arm after the oblique outward below, through the anterior edge of the brachioradialis muscle to reach the elbow. Between the posterior edge of the biceps and the anterior edge of the biceps, i.e., the lateral septum enters, and the radial nerve can be found at the posterior edge of the septum. 2. Elbow exploration: make an arc-shaped notch on the anterolateral side of the elbow and enter at the interval between the biceps and brachialis muscles and the radial longissimus carpi radialis. At the medial edge of the brachioradialis muscle, there is a fan-shaped artery from the brachial artery to the brachioradialis muscle obliquely spanning the superficial surface of the radial nerve, which can be cut off by ligature. Its deep surface can be seen that the radial nerve is divided into two deep and superficial branches, and the deep branch penetrates the posterior muscular canal, and the Frohse arch that crosses the surface of the deep branch of the radial nerve can be cut off to reveal the deep branch of the radial nerve. 3, forearm segment exploration: a posterior lateral forearm incision can be made, from under the elbow joint to the midpoint of the dorsal forearm, the deep branch of the radial nerve is revealed between the proximal brachioradialis muscle and the radial longissimus carpi radialis, which can be seen to turn to the dorsal side of the forearm, penetrate between the two layers of the posterior rotator muscle and travel distally. Along the way, it sends branches to innervate the posterior rotator muscle, thumb and finger extensor muscles. This branch is divided into several branches and is so small that once it is injured, surgical repair is difficult. 4.Functional reconstruction: Tendon displacement functional reconstruction can be considered in the following cases: (1), no obvious signs of recovery after nerve repair; (2), deep branch injury cannot repair the nerve; (3), advanced radial nerve injury, the extensor group has been completely atrophied, no possibility of recovery. Commonly used methods are: rotary anterior circular muscle shift and radial carpal long and short extensor tendon suture, restore wrist extension function; ulnar carpal extensor muscle shift and general extensor tendon suture, restore finger extension function; palmaris longus muscle shift is located in thumb long extensor tendon suture, restore god thumb function; radial carpal flexor muscle shift is located in thumb long extensor muscle, thumb short extensor suture, restore thumb abduction function. Flexion of the wrist can be strengthened by the superficial finger flexors of the ring finger.