Abstract: Objective To evaluate the effect and safety of nebulized magnesium sulfate (MgSO₄) combined with albuterol sulfate in the treatment of moderate to severe asthma attacks in children. Methods Ninety-nine children with acute attack of bronchial asthma were randomized into three groups:MgSO₄ nebulization (group M), salbutamol nebulization (group S), and combination (group M+S). The aerosol inhalation based on the routine treatment was performed in all groups. The FEV1, PEF, FEV1% and PEF%, clinical efficacy, time of mechanical ventilation and ICU treatment, hospital stay and the incidence of adverse reactions were compared among the three groups. Results After the treatment, the absolute values (FEV1 and PEF) and the predicted percentage (FEV1% and PEF%) in all the three groups were significantly increased, among which the improvement of the group M+S was the largest, followed by the group S, and the group M were the smallest. The total effective rates of group M, group S and group M+S were 66.67%, 69.70% and 93.94%, the effective rate of group M+S was significantly higher than those of group S and group M (P<0.016 7), but no significant difference between group S and group M (P>0.016 7). The hospitalization time, the use rate and use time of mechanical ventilation and ICU treatment were significantly lower in the group M+S than group M and group S (P<0.05). There were no significant differences in the treatment-related adverse effects rates three groups (12.12%, 9.09% and 18.18%, P>0.05). Conclusion In the treatment of moderate to severe asthma attacks in children, the use of magnesium sulfate combined with salbutamol sulfate inhalation has a better effect and good safety, can significantly improve lung function, and reduce the use of mechanical ventilation.