Peroneal nerve necrosis is caused by peroneal nerve injury, common symptoms are sensory and motor dysfunction and deformity. 1. Sensory dysfunction: common peroneal nerve innervates the anterolateral calf and the dorsal skin of the foot, which leads to sensory impairment of the anterolateral calf and the anterior and medial dorsum of the foot after injury. 2. Motor dysfunction: the common peroneal nerve innervates the anterolateral muscle group of the calf, and if injured, it will cause loss of toe extension function. 3. Deformity: common peroneal nerve injury, extensor muscle paralysis of the anterolateral calf muscle group, ankle dorsiflexion, valgus dysfunction, foot inversion and prolapse deformity. If there is peroneal nerve injury or necrosis, please consult a doctor in time to find out the cause of the disease, under the guidance of the doctor’s treatment and functional exercise, so as not to delay the condition.