Objective To explore the influencing factors of the pulse therapy effect of methylprednisolone in children with severe mycoplasma pneumoniae pneumonia (MPP). Methods: The clinical data of 119 children with severe MPP admitted to our hospital from January 2022 to March 2024 were retrospectively collected. All the children patients were given methylprednisolone pulse therapy on the basis of conventional treatment. The children were divided into the ineffective group and the effective group according to the different therapeutic effects after 7 days of treatment. Collect and compare the baseline data of the ineffective group and the effective group. The influencing factors of ineffectiveness of methylprednisolone pulse therapy in children with severe MPP were analyzed by Logistic regression model. Results: Among 119 children with severe MPP, after conventional treatment combined with methylprednisolone pulse therapy, 96 children were effectively treated. There were 23 cases of children who were ineffective in treatment. The proportion of lung lobes with the affected lung range ≥2/3 in the ineffective group was significantly higher than that in the effective group (P < 0.05). The proportions of procalcitonin (PCT) ≥13.28ng?L-1, interferon -γ (IFN-γ) ≥184.25pg?mL-1, and serum amyloid A (SAA) ≥133.41mg?L-1 in the ineffective group were significantly higher than those in the effective group (P < 0.05). There were no significant differences in age, gender, body mass index, disease duration, fever duration and pleural effusion between the two groups (P > 0.05). The results of Logistic regression analysis showed that the affected lung range ≥2/3 of the lung lobes, PCT≥13.28ng?L-1, IFN-γ≥184.25pg?mL-1, and SAA≥133.41mg?L-1 were risk factors for ineffective methylprednisolone pulse therapy in children with severe MPP (OR > 1, P < 0.05). Conclusion: The influencing factors for the ineffectiveness of methylprednisolone pulse therapy in children with severe MPP are the affected lung range ≥2/3 of the lung lobe, PCT≥13.28ng?L-1, IFN-γ≥184.25pg?mL-1, and SAA≥133.41mg?L-1.