Abstract: Objective To study the preventive and curative effects of improved posture combined with 0.02% chlorhexidine oral care on ventilator-associated pneumonia (VAP). Methods Totally 170 patients with mechanical ventilation time >48 h after breath tube intubation who were treated in the ICU of our hospital from February, 2016 to February, 2018 were selected. Regular oral cavity nursing was given to patients in the routine nursing group, and improved position in combination with concentration of 0.02% chlorhexidine acetate solution for oral care to patients in the combined nursing group. Pulmonary infection after nursing, length of stay in ICU, oral inflammation, mechanical ventilation time and GCS score, incidence of patients with bacteria, sputum scab formation rate, and incidence of VAP were calculated. Results The pulmonary infection score and length of stay in ICU in the combined care group were significantly lower than those in the conventional care group (P<0.05). The incidence of oral inflammation in the combined care group was significantly lower than that in the conventional care group (P<0.05). The incidence of oropharyngeal and intratracheal colonization in the combined care group was significantly lower than that in the conventional care group (P<0.05). The sputum scab formation rate and VAP incidence in the combined nursing group were significantly lower than those in the conventional nursing group (P<0.05). Conclusion The use of modified postures and concentration of 0.02% chlorhexidine solution can better reduce the incidence of ventilator-associated pneumonia in severe patients under the condition of mechanical ventilation, providing great help for patients' rehabilitation and disease treatment.