Abstract: Objective： To investigate the clinical application effect of protective pulmonary ventilation in severe thoracic trauma combined with acute respiratory distress syndrome (ARDS)， and to analyze the clinical efficacy. Methods： Eighty patients with severe thoracic trauma complicated with ARDS in intensive care unit (ICU) of our hospital were selected as the object of study. They were randomly divided into the control group and the observation group on average， which were treated with conventional mechanical ventilation and protective pulmonary ventilation respectively. The clinical efficacy， blood gas index， respiratory dynamics index and hemodynamic index at different time points before and after treatment were compared between the two groups. Results： The mechanical ventilation time (MVT) and ICU monitoring time after treatment in the observation group were shorter than those in the control group (P<0.05). The incidence of ventilator-associated pneumonia (VAP) and mortality in the observation group were lower than those in the control group (P<0.05). During the period from the beginning of treatment to 1 min after treatment， the average levels of mean arterial pressure (MAP) and cardiac output（CO） in the observation group were lower than those before treatment (P<0.05). 5 min after treatment， all the indexes recovered to the pre-treatment level (P>0.05). The level of Pplat at 24 h after treatment in the observation group was lower than that before treatment (P<0.05)， and at 48 h and 72 h after treatment were lower than that in the control group (P<0.05). The level of PIP at 12 h after treatment in the observation group was lower than that before treatment (P<0.05), and was lower at 12 h，24 h, 48 h and 72 h after treatment compared with that in the control group. The level of Cst in the observation group after treatment was higher than that before treatment, and at the same time point was higher than that in the control group (P<0.05). After treatment, PaO2 and PaO2/FiO2 in both groups were higher than those before treatment, and the level of PaO2 and PaO2/FiO2 in the observation group were higher than those in the control group at the same time point after treatment (P<0.05). The pH and PaCO2 before and after treatment had no statistical difference between the two groups (P>0.05). Conclusion: Protective pulmonary ventilation can improve the clinical efficacy, blood gas, respiratory dynamics and hemodynamics of patients with severe thoracic trauma combined with acute respiratory distress syndrome.