Objective To investigate the effect of combined use of sodium bicarbonate and ambroxol on airway humidification in neonatal mechanical ventilation.Methods Randomly selected 52 patients with mechanical ventilation,and were randomly divided into experimental group and control group with 26 cases in each group.The experimental group used 0.45％ sodium combined with ambroxol,used microinjection pump in the offline state of continuous airway humidification and the use of sodium bicarbonate for airway cleaning.While the control group used the traditional method,in an offline state of continuous airway humidification.Observed 2 groups of sputum viscosity and ventilator-associated pneumonia (VAP) and the incidence of complications.Results The experimental group patients sputum viscosity was significantly lower than that of control group,the difference was statistically significant (7.7％ vs 38.5％ ; x2 =6.93 ; P ＜ 0.01).Mechanical ventilation complication rate in experimental group was significantly lower than that in control group(15.4％ vs 42.3％ ; x2 =4.59;P ＜ 0.05).Conclusions For mechanical ventilation of the newborn with ambroxol continuous airway humidification and combined use of sodium bicarbonate and airway cleaning can effectively reduce sputum viscosity,and reduce the occurrence of ventilator-associated pneumonia.