Abstract: As a representation of modern criminal law, the principle of modesty in criminal law plays an important guiding role in the scope of regulation, value orientation and theoretical system of criminal law. However, the theory and practice have not reached a consensus on the principle of modesty in criminal law, and there are even flaws and deviations. Therefore, it is necessary to standardize the principle of modesty in criminal law, clarify the role of the principle of modesty in criminal law, and restore the modesty of criminal law. The value orientation of the principle of restraint makes the principle of restraint in criminal law integrate the characteristics of pertinence, certainty and practicality of legal rules. Standardizing the principle of modesty in criminal law is helpful for judicial adjudicators to properly handle the relationship between problem thinking and system thinking, and the relationship between criminal law stability and individual case legitimacy in the face of criminal-civilian conflicts, so as to maintain legal integrity, authority and stability. To standardize the principle of modesty in criminal law, on the basis of clarifying the basic types of jurisprudential conflicts, it is necessary to comprehensively consider the sources of conflicts between criminal law and civil law in the evaluation of illegality and the delineation of the scope of interest protection. The level and the scope of interest protection are delimited, and the standardized rules of the principle of modesty in criminal law are constructed, so that the principle of modesty in criminal law can guide the characterization of cases in judicial practice under the concept of the unity of legal order.