In order to understand the influencing factors of hospitalization expenses of cross-provincial cancer patients, based on the framework of social ecology theory, this paper uses descriptive statistics and mixed linear model to explore the social ecological factors affecting the hospitalization expenses of cross-provincial cancer patients. The results showed that the proportion of patients with malignant tumors of digestive organs in cross-province medical treatment was the highest ( 18.66 % ), and the average hospitalization cost of tumors with uncertain or unknown dynamics was the highest ( 45535.24 yuan ). The hospitalization expenses were affected by the type of tumor in personal characteristics, the number of hospitalization days in personal behavior, the distance of medical treatment at the environment level, and the actual reimbursement ratio at the policy level ( P < 0.05 ). The hospitalization cost of cancer patients in different provinces is relatively high, which is affected by many social and ecological factors. It is necessary to analyze the influencing factors of hospitalization expenses from the perspective of individual cancer patients and their ecological environment, so as to rationally allocate health resources and guide patients to seek medical treatment.