Currently, medical insurance fraud behavior is regulated by administrative law and criminal law. When the social harmfulness reaches a certain level, it will be convicted and punished as the crime of fraud. Excessive diagnosis and treatment is one of the means to carry out medical insurance fraud, but it has not been explicitly stipulated in the regulatory legal documents in the criminal field at present. Moreover, the judgment standard for "excessive" and the discretion benchmark for criminal liability fines also need to be supplemented. The criminal regulation of medical insurance fraud behavior should be improved based on the infringement of legal interests by excessive medical treatment and the particularity of medical insurance fraud behavior compared with other fraud crimes. First, the regulation of excessive medical treatment should be strengthened to prevent insurance fraud by excessive medical treatment behavior from the source. The judgment standard for "excessive" should be clearly defined in legislation, and relevant crimes related to medical insurance fraud can also be added. Second, the rules for conviction and punishment of medical insurance fraud behavior should be improved. The general clause should be interpreted in light of its purpose and restricted. When the insurance fraud behavior committed by excessive medical treatment infringes on the interests of life and health, the rule of combined punishment for several crimes should be applied. Third, the discretion benchmark for fines should be refined. Different fine ranges should be set according to the degree of harm of different behaviors. By improving the judgment standards and discretion benchmarks of medical insurance fraud behavior in criminal legislation, it is conducive to realizing the criminal regulation of medical insurance fraud committed through excessive medical treatment.