ObjectiveTo observe the clinical efficacy of Shengmaisan combined with polymyxin B in the treatment of carbapenem-resistant gram-negative bacillus infection with sepsis complicated with severe acute respiratory distress syndrome. MethodA total of 90 patients suffering from carbapenem-resistant gram-negative bacillus infection with sepsis complicated with severe acute respiratory distress syndrome were randomly divided into a control group and an observation group， with 45 cases in each group. The control group was treated with polymyxin B， and the observation group was treated with Shengmaisan combined with polymyxin B. The treatment course of both groups was seven days. The infection-related indicators ［white blood cell （WBC） count， procalcitonin （PCT）， neutrophil apolipoprotein （HNL）］， inflammatory factors ［interleukin-6 （IL-6）， serum chemokine ligand 2 （CXCL2）］， and T lymphocyte subpopulations （CD3⁺， CD4⁺， CD8⁺， and CD4⁺/ CD8⁺ value）， acute physiological and chronic health Ⅱ （APACHE Ⅱ） score before and after treatment， as well as bacterial clearance rate and 28-day survival rate after treatment were observed. Result① The experiment was completed， and 81 cases were included， including 41 cases in the observation group and 40 cases in the control group. The general data of the two groups were comparable. ② The bacterial clearance rate of the observation group and the control group was 75.6% （31/41） and 52.5% （21/40）， respectively， and the observation group was higher than the control group （χ²=4.7， P<0.05）. ③ The WBC count， PCT， HNL， IL-6， CXCL2， and APACHE Ⅱ scores of the observation group and the control group all decreased after treatment （P<0.05）. Except for the WBC count， the PCT， HNL， IL-6， CXCL2， and APACHE Ⅱ scores of the observation group were lower than those of the control group （P<0.05）. ④ The values of CD3⁺， CD4⁺， and CD4⁺/CD8⁺ in the observation group were increased after treatment （P<0.05）， and CD8⁺ was decreased （P<0.05）. In the control group， only CD3⁺ value was increased （P<0.05）. The values of CD3⁺， CD4⁺， and CD4⁺/CD8⁺ in the observation group were higher than those in the control group， and the value of CD8⁺ was lower than that in the control group （P<0.05）. ⑤ The 28-day survival rate in the observation group was higher than that in the control group （χ²=4.3， P<0.05）. ConclusionShengmaisan combined with polymyxin B in the treatment of carbapenem-resistant gram-negative bacillus infection with sepsis complicated with severe acute respiratory distress syndrome can better clear bacteria， control infection， reduce the level of inflammatory factors， regulate the immune state of the body， and improve the short-term prognosis.