Objective To study the therapeutic effect and safety of methylprednisolone sodium succinate on children with severe Mycoplasma pneumoniae pneumonia（SMPP）．Methods A total of 108 children with SMPP admitted to Changsha Central Hospital from January 2021 to December 2022 were divided into two groups by random number table method．The control group（54 cases）was treated with conventional therapy,and the study group（54 cases）was treated with conventional therapy combined with methylprednisolone sodium succinate．The clinical effects of the two groups were compared．Results After treatment,the levels of inflammatory factors in the study group were lower than those in the control group,and lung function indicators and health status scores were higher than those in the control group．The disappearance time of fever,cough,lung rales and lung shadows was shorter than that in the control group（P<0.05）．There was no statistically significant difference in the incidence of adverse reactions between the two groups（P>0.05）．Conclusions The application of methylprednisolone sodium succinate treatment can accelerate the relief of symptoms in children,improve the body's inflammatory response and lung function,and has high safety．