Objective: To analyze the risk factors of adverse events after chemotherapy for hematological malignancies. Methods: A total of 135 patients with malignant tumor chemotherapy admitted to the Department of Hematology of No. 904 Hospital of Joint Logistics Support Force from January 2020 to January 2021 were selected, and the clinical data of all patients were retrospectively analyzed. Univariate and multivariate logistic regression analysis was used to analyze the occurrence of adverse events in all patients after chemotherapy to explore their independent risk factors and establish related risk prediction models. Results: Seventy of 135 patients had adverse events after chemotherapy, accounting for 51.85%. Univariate analysis showed that there was a statistically significant difference in the incidence of adverse events after chemotherapy in patients with hematological malignancies with different degrees of liver damage and history of hypertension, active infection, abnormal blood coagulation, and obesity (P<0.05). After multivariate analysis, liver damage, active infection, abnormal blood coagulation, and obesity were independent risk factors that led to adverse events after chemotherapy (P<0.05). Conclusion: Liver damage, active infection, abnormal blood coagulation function, and obesity are independent risk factors for adverse events after chemotherapy, and multivariate analysis can predict the risk of adverse events after chemotherapy.