The improvement of the medical security mechanism for rare diseases is an important part of the high-quality development of a multi-level medical security system with Chinese characteristics. In this paper, hemophilia patients and their medical security were the research objects. Through field investigation, case interview and other research methods, the paper discussed the treatments, medication methods, medical institution selection and basic medical insurance participation of rare disease patients. At the same time, it comprehensively analyzed the medical security policies of hemophilia patients in China, including the access to the national medical insurance drug list, the serious illness insurance system for urban and rural residents, the medical insurance and assistance system for major and very serious diseases, and the local hemophilia medical security policies. Based on these analyses, policy suggestions were put forward to support the innovation and development of rare disease drugs, improve the access mechanism of medical insurance drug catalogue, establish and improve a sound rare disease security system, and strengthen the construction of diagnosis and treatment capacity, so as to promote the improvement of the rare disease medical security mechanism.