Objective:　To explore the importance of mechanic al ventilation (MV) in treating multiple trauma mainly accompanied with cerebral injury and improve the treatment level.rn　　Methods:　All 116 patients who suffered from multiple trauma acc ompanied with mainly cerebral injury were analyzed. Rank correlation and Chi-sq uare test were made between MV with GCS, ISS, and whether shock or not.rn　　Results:　The MV was correlated with GCS, ISS scores, and whethe r shock or not markedly. Furthermore, when GCS≤8, the ratio of MV was about 70% . When ISS≥35, the ratio of MV was about 85%.rn　　Conclusions:　During the treatment of multiple trauma accompanie d with cerebral injury, the principle of “early MV, early withdraw” and “indi vidualism” should be insisted on. For patients accompanied with shock, the opti mum PEEP is very important. Proper and active MV is of great importance and can improve the treatment level markedly.