Objective: To analyze the medical security effect of catastrophic illness in Guangxi. Methods: Using the statistical data of special treatment funds for outpatient special chronic diseases and major diseases in Guangxi, the medical security effect of catastrophic illness in different regions and different diseases was analyzed by descriptive statistical method. Results: After comprehensive compensation of basic medical insurance, serious diseases insurance and medical assistance, the reimbursement rates of total medical expenses for special chronic diseases and serious diseases in Guangxi were 79.23 % and 79.10 %, respectively. The reimbursement rates of the triple system for outpatient special chronic diseases and special treatment of serious diseases in each region are 69 %–87 % and 75 %–83 %, respectively. The diseases with a small number of treatment but a high proportion of self-paid are congenital cleft lip and palate, neuroblastoma and other diseases. Conclusion: It is suggested to strengthen the comprehensive security of the triple system and improve the security level of catastrophic illness. All regions should speed up the pooling level, improve the level of information service, and improve the dynamic adjustment of drug catalogue to improve the level of medical security for catastrophic illness.