OBJECTIVE： To observe the effects of pumping different dose ambroxol hydrochloride on the infection control and prognosis of patients with ventilator-associated pneumonia. METHODS： 80 patients with ventilator-associated pneumonia were randomly divided into control group （41 cases） and observation group （39 cases）. All patients received conventional symptomatic treatment， including oxygen inhalation， atomization， nutritional support， maintaining steady state equilibrium and effective antibiotics based on the bacterial culture results. Based on it， control group was given ambroxol hydrochloride 30 mg， intravenously infused， tid； observation group was given ambroxol hydrochloride 300 mg， intravenously pumped within 6 h， qd. All patients were treated for 2 weeks. Clinical efficacy in 2 groups was observed， pulmonary infection score （CPIS）， oxygenation index， IL-6 level，ICU hospitalization time， mechanical ventilation time and the incidence of adverse reactions in 2 groups were recorded. RESULTS： The cure rate in observation group was significantly higher than control group， hospitalization time and mechanical ventilation time were significantly shorten than control group， with statistical significance （P＜0.05）. After treatment， CPIS， IL-6 scores in 2 groups were significantly lower than before， and observation group was lower than control group； oxygenation index was significantly higher than before， and observation group was higher than control group， with statistical significance （P＜0.05）. And there was no significant difference in the incidence of adverse reactions between 2 groups（P＞0.05）. CONCLUSIONS： Pumping high-dose ambroxol hydrochloride has better efficacy than intravenous infusion of conventional dose in the treatment of ventilator-associated pneumonia than conventional dose， it can increase the control efforts for injection， improve prognosis， and does not increase the incidence of adverse reactions.