Objective. To investigate the influencing factors of pneumonia when pediatric leukemia patients are hospitalized and propose coping strategies. Methods. A retrospective study and analysis of the inpatient medical records of 183 children with leukemia in our hospital from August 2017 to August 2020. A total of 93 cases were in the case group of children with pneumonia, and the rest were 90 cases in the control group. Case data from two groups of children were compared, and the monofactor analysis of pneumonia occurred. The P < 0.05 was selected for its multivariate logistic regression analysis, and its coping strategy was proposed. Results. After multivariate logistic retrospective analysis, it was found that the main influencing factors were neutrophils, white blood cells, vitamin D, and cellular immunity ( P < 0.05 ). A review of the two sets of pathological data found that high doses of cytarabine reduced the incidence of pneumonia in children with leukemia ( P < 0.05 ). Conclusion. A timely understanding of the influencing factors of pediatric diabetes mellitus and pneumonia and the early application of cytarabine can reduce the incidence of pneumonia during the child’s hospitalization.