Objective To explore the risk factors in the prognosis of patients with severe multiple trauma related factors.Methods Ninety-three patients with severe multiple trauma(ISS score≥16 points) were selected as our subjects,who all hospitalized in the second hospital affiliated to Dalian medical University.Among of which,38 cases' ISS score was 16-25,and 55 cases' ISS score was higher and equal to 25.Clinical data and general information were recorded.ISS score,APACHE Ⅱ score and 6 h lactate clearance rate score were measured.Results Twenty-seven dead among these 93 cases and the mortality was 29.03％.There were significant differences in terms of ISS score,APACHE Ⅱ score,lactate level when entering ICU,6 h lactate level and 6 h lactate clearance rate between death patients (27 cases) and survival patients (66 cases) (t =9.846,9.812,7.112,7.012,9.831 ; P ＜ 0.001).In multiple organ dysfunction syndrome (MODS) patients,the mortality of ISS score:16-25 group was different from that of ISS score≥25 (15.78％ (6/38) vs.35.18％ (21/93),x2 =21.52,P ＜0.001).Among the 93 cases of severe multiple trauma,35 cases with MODS(37.6％ (35/93)),and 20 cases of which were dead(57.1％ (20/35)).There was statistic difference between MODS group(35 cases) and non-MODS(58 cases) in term of mortality(37.6％ (35/93) vs.12.1％ (7/58) ;x2 =21.52,P ＜ 0.001).Multivariate logistic regression analysis showed that the ISS score,APACHE Ⅱ score,6 h lactate clearance rate and MODS were independently prognostic correlation factors (P ＜ 0.05).Operating characteristic curve (ROC) showed that AUC of ISS score was 0.735 (95 ％ CI 0.629-0.842),of APACHE Ⅱ score was 0.888 (95％ CI 0.821 =0.956),of 6 h lactate clearance rate score was 0.951 (95％ CI 0.906 -0.997).Conclusion The factors of ISS score,APPCHE Ⅱ assessment,6 h lactate clearance rate,the occurrence of MODS are independent prognostic factors.