The Criminal Law Amendment (11)(2020) and the Interpretation of Certain Questions of the Law Applying to Criminal Cases of Environmental Pollution (hereinafter referred to as "Judicial Interpretation" (2016)) issued by the "Two Highs" provide for the principle of "punishment for the most serious crime" for imaginative joinder of offenses in environmental pollution category. Through the structural analysis of the imaginative joinder of offenses in environmental pollution category, it is concluded that the principle can't "comprehensively" evaluate the behavior of imaginative joinder of offenses and the offended objects and infringed rights and interests. Accordingly, starting from the basis of criminal law and criminal policy, the study redefines the principle of judicial punishment for imaginative joinder of offenses in environmental pollution category as the principle of "comprehensive punishment for the most serious crime", and expands its application in conviction, sentencing and puts forward the requirements for the interpretation of judicial instruments. When the crime of polluting the environment has not been convicted as a serious crime, the study further explores the special content and form of "comprehensive punishment for the most serious crime" for imaginative joinder of offenses in environmental pollution category.