Symptoms: 1. Difficulty in lifting the calf and toes, dragging the calf when walking, easy to break the foot; 2. Numbness and pain in the skin of the lateral calf and dorsum of the foot; 3. Inability to lift the big toe; 4. If there is a combination of plantar sensory disorder, there may be a combination of ankle canal syndrome. The common peroneal nerve travels lateral to the N fossa, below the small head of the fibula, and enters the peroneal canal. Trauma, frequent cross-legged sitting, diabetes, connective tissue disease, chemotherapy, etc. can cause the common peroneal nerve to become entrapped at the peroneal canal, causing injury and paralysis of the common peroneal nerve. Diagnosis: Diagnosis can be confirmed by foot drop, sensory deficits in the lateral and dorsal calf, and electromyography showing reduced conduction velocity of the common peroneal nerve or failure to elicit evoked potentials. Conservative treatment: 1, if the nerve is mildly damaged, it can usually recover within 3 months after the injury; 2, you can use nerve-nourishing drugs, such as vitamin B1 and methylcobalamin tablets orally, or you can inject rat nerve growth factor; 3, most importantly, you should wear corrective shoes to avoid ankle injuries; 4, you should pay attention to the temperature when washing your feet and physiotherapy to avoid skin burns due to sensory impairment of the calf and dorsal foot. Surgery: If the symptoms do not improve 3 months after the injury, electromyography shows muscle loss of innervation and positive tinel sign, surgery should be performed in time. Surgery can restore sensation, relieve pain and improve the motor function of the limb. A 2-cm incision was made below the calf fibular tuberosity and nerve release was performed endoscopically. Surgical efficacy: The surgical efficacy is related to the preoperative course of the disease and symptoms, usually 80-90% of patients have significant improvement. In cases of prolapsed foot for a long time, the results may be poor. Therefore, early and aggressive treatment and timely surgery if necessary are recommended.