Objective To analyze the curative effect of mechanical ventilation for severe pulmonary contusion and imaging changes. Methods One hundred and twenty patients with severe pulmonary contusion who underwent mechanical ventilation in the hospital from January 2015 to January 2018 were enrolled in the study. The respiratory rate (RR), heart rate (HR), blood gas analysis indicators [partial pressure of blood oxygen (PaO2), oxygenation index (PaO2/FiO2), partial pressure of carbon dioxide (PaCO2)], recovery [time for oxygen saturation (SpO2) restoring to 95%, disappearance of wet rales, mechanical ventilation time, length of ICU stay] and clinical efficacy were observed. Imaging changes before and after treatments were analyzed. Results The RR, HR and PaCO2 were significantly decreased after 24 hours of treatment (P<0.05), while PaO2 and PaO2/FiO2 were significantly increased (P<0.05). The time for SpO2 restoring to 95%, disappearance of wet rales, mechanical ventilation time and length of ICU stay were (27.46±2.83) min, (61.78±6.35) min, (5.24±0.67) days and (7.12±0.76) days, respectively. The excellent, good and poor rates of efficacy were 87.50%, 8.33% and 6.67%, respectively. Multiple organ dysfunction syndrome caused death. CT images clearly showed the extent, density and development of pulmonary contusion. Conclusion Mechanical ventilation therapy can effectively improve the respiratory and blood gas analysis indexes in patients with severe pulmonary contusion, promote recovery of SpO2 and clinical signs and reduce the mortality rate, with good curative effect. CT images are of guiding value for early diagnosis and treatment and evaluation of prognosis.