Abstract: Although various countries have established the exclusion rules of illegal confession,there are many differences.This paper adopts the method of difference selection and specific interpretation in comparative law to compare the exclusion rules of illegal confession in the legislation and practice of various countries. By deconstructing the exclusion rule of illegal confession,this paper analyzes and comments the connotation,extension,identification of the subject of illegal confession,identification of illegal confession and its proof. The definition of illegal confession in China has not yet included the criterion of arbitrariness. The identification of illegal confession subjects does not take “causal relationship” as a consideration factor,and the identification of illegal confession also does not pay enough attention to the mental torture suffered by criminal suspects. Proof of the legality of an confession has not yet made it clear that the standard of proof provided by the defense is sufficient to cause a judge to doubt.