Abstract: The frequent occurrence of fraudulent medical insurance funds has done great harm to the operation and development of the medical insurance system. The paper first sorts out the cases of medical insurance fund fraud which have great effect on the society in recent years. Then it analyzes the core logic of fraud insurance from the perspective of moral hazard. With the help of COSO(The Committee of Sponsoring Organizations of the Treadway Commission) risk management framework, the paper puts forward the anti-fraud system of the medical insurance fund based on the process, including the sound prevention mechanism, the effective identification and measurement, the intensive investigation and the strict punishment and restraint. With this framework, the paper systematically introduces the experience of the international medical insurance fund against fraud. It is found that many countries or regions have formed a multi-level precision recognition mechanism to carry on a scientific and prudent investigation and evaluation and construct an omni-directional anti-fraud punishment and restraint network. For this reason, the paper suggests that China urgently need to establish the legal level of medical insurance anti-fraud norms. The government should absorb the market and social forces, introduce third party services to promote intelligent auditing of medical insurance, build anti-fraud monitoring network by using large data and other technologies, and actively create a national cultural atmosphere for the anti-fraud. At the same time, it is necessary to further deepen the medical and health management system and the medical circulation system to create a harmonious system environment for preventing medical insurance fraud.