Discuss the electromyography and imaging characteristics of Hirayama disease，and improve clinicians’ awareness of the disease. Methods A retrospective analysis of clinical data of five cases of Hirayama disease patients in our hospital，analyze its clinical manifestations，EMG and imaging features. Results 5 patients were male，age 18 to 28 years old，（3 cases） unilateral，bilateral involvement in two cases of asymmetry. Five patients showed the hand and forearm muscle weakness with atrophy，forearm ramp-like changes，with cold paralysis. Motor nerve conduction delay mainly ulnar nerve terminal during latent，median nerve，ulnar nerve compound muscle action potential （the CMAP） amplitude decreased，no motor nerve conduction block；sensory nerve conduction were normal. Needle electrode EMG neurogenic damage，abnormal muscle mainly in the C7-T1 segment dominated area. MRI in the neutral position of the cervical spine in 5 patients showed that the physiological curvature was straightened or the spinal cord was slightly thinned；2 cases showed LOA phenomenon in the cross section；5 cases showed different degrees of compression of the cervical spinal cord forward and the epidural space signal shadow in the flexion position，enhanced scanning Abnormal enhancement in the epidural space can be seen. Conclusion According to the clinical manifestations of Hirayama disease combined with its characteristic electromyography and MRI features，early diagnosis of Hirayama disease can be made.