Objective To investigate cranial decompression under temporal muscle in very-low position with large bone flap combined with mild hypothermia for severe cranial trauma.Methods 88 severe brain injury patients (GCS ≤ 8 ) were randomly divided into two groups,mild hypothermia group( n =48) and non-mild hypothermia group ( n =40),both presented with cranial decompression under temporal muscle in very-low position with large bone flap.Data of patients,GCS increment,rate of brain cistern display,rate of pupil shrink and therapeutic effect were ananlyzed.Results The treatment group showed better effect compared with the oontrol group(P＜0.05).Condusion The therapy of cranial decompression under teniporal muscle in very-low position with large bone flap combined with mild hypothennia showed the advantage of depressing intracranial pressure,reducing crerebral edema and improving the therapeutic effect of severe brain injury patients.