Objective To analyze the effects of montelukast sodium tablets combined with magnesium sulfate injection on pulmonary function in patients with bronchial asthma. Methods 96 patients with bronchial asthma were divided into study group and control group according to the simple randomized grouping method, with 48 cases in each group. Control group was given conventional bronchial asthma, and study group was given montelukast sodium tablets and magnesium sulfate injection on the basis of the former. Thepulmonary function indexes [ratio of forced expiratory volume in 1st second(FEV1) in predicted value, ratio of forced expiratory volume in 1st second in forced vital capacity(FEV1/FVC), peak expiratory flow(PEF)], symptom relief time(wheezing, cough, chest tightness) and psychological status [Clinical Symptom Checklist(SCL-90)] were compared between the two groups before treatment and after 3 months of treatment. Results After 3 months of treatment, thelevels of pulmonary function indexes (FEV1, FEV1/FVC, PEF) in the two groups were significantly higher than those before treatment, and the improvements in study group were higher than those in control group(P<0.05), and the symptom relief time and SCL-90 score were significantly lower than those before treatment, and the reductionsin study group were higher than those in control group(P<0.05). There were no serious adverse reactions such as dyspnea and blood pressure reduction. Conclusion Montelukast sodium tablets combined with magnesium sulfate injection has significant treatment effects on patients with bronchial asthma, and it is beneficial to disease outcomes of patients.