Objective  To explore the effects of protective mechanical ventilation on the respiratory mechanics and pulmonary oxygenation function of general anesthesia patients with high risk of postoperative pulmonary complications. Methods  A total of 120 general anesthesia patients with high risk of postoperative pulmonary complications were enrolled and randomly divided into the research group (n=60) with a tidal volume of 6.00 mL/kg, respiratory rates of 15/min, PEEP of 6 cmH2O, I∶E of 1∶1.5, one recruitment maneuver per hour after operation, spontaneous mode, pressure of 30 cmH2O for 30 s and then resuming the original mode, and the control group (n=60) with a tidal volume of 10.00 mL/kg, respiratory rates of 12/min, PEEP of 0 cmH2O, and I∶E of 1∶1.5. Arterial blood samples of two groups were drawn after mechanical ventilation of 30 min (T1) and end of operation (T2) for blood gas analysis. According to the results, oxygen partial pressure, tidal volume, peak airway pressure, and plateau pressure were recorded and oxygenation index, static compliance, and dynamic compliance were calculated. Results  Compared with the control group, the plateau pressure of the research group during T2 was significantly lower, static compliance and oxygenation index were higher, postoperative pulmonary complications were much less, and ICU stay was shorter (P<0.05). Conclusion  Protective mechanical ventilation can improve lung compliance and oxygenation and reduce postoperative pulmonary complications.