1, the affected limb examination: pay attention to the presence of wounds and their location, scope, depth, surrounding soft tissue condition; the presence of infection; the presence of lumps, etc., and the presence of combined injuries (such as fractures, dislocations). If the wound has healed or there is no wound, only the scar condition, blood flow and functional status should be observed. In addition, the posture of the limbs can also reflect different peripheral nerve injuries, such as radial nerve injury can appear drooping wrist; ulnar nerve injury can appear claw-like fingers; median nerve injury can appear “ape hand” deformity; common peroneal nerve injury can appear foot drop. 2.Motor function examination: muscle strength grading. 3, sensory function examination: general examination of pain and tactile sensation, should be compared bilaterally. Solid sensation and shallow touch are fine sensation, pain and deep touch are coarse sensation, after nerve repair, the recovery of coarse sensation is earlier and better. The degree of sensory dysfunction can also be distinguished by the 6-level method, i.e. S “0” level: no sensation at all; S “1” level: deep nociception exists; S “2” level: nociception and partial tactile sensation; S “3” level: complete pain and tactile sensation; S “4” level: complete pain and tactile sensation, and two points of distinction, but the distance is large; S “5” level: completely normal sensation. 4, reflexes: can be caused by nerve or muscle damage and tendon reflexes are reduced or disappeared. 5, nutritional changes: after peripheral nerve injury, its innervation area can appear low skin temperature, no sweating, atrophy, nail cresting and claw-like bending, also prone to traumatic chronic ulcers, frostbite, etc.. The area of no sweat or little sweat generally corresponds to the range of sensory loss. 6, nerve stem percussion test (Tinel’s sign): after nerve injury or repair of damaged nerve, tap the nerve in the corresponding plane, its distribution area will appear radiating pain and hyperalgesia, this is the nerve axon regeneration faster than myelin regeneration, the nerve axon exposed, the allergic phenomenon when being percussion. This sign has a greater significance in the diagnosis of nerve injury and the process of nerve regeneration. As the regeneration process continues to progress, this allergic phenomenon can be induced by percussion at the distal corresponding site.