The special actions of the medical insurance departments usually specify inspection periods, but administrative punishment cases have clear requirements on the time limit for illegal acts. How to deal with the relationship between the inspection period and the investigation limitation is a direct problem faced by the authorities. Before there is other provisions in the field of medical insurance, we must abide by the legal principle and correctly distinguish three cases of illegal acts, which are independent occurrence, continuous occurrence and continuous state, so as not to pervert the law, and deal with all kinds of medical insurance administrative punishment cases according to laws and regulations. From the perspective of administrative law enforcement, this paper puts forward some suggestions on the investigation limitation of medical insurance administrative punishment cases.