The principle of in dubio pro reo has a profound historical source of Chinese and foreign law and a comparative legal basis,embodies the presumption of innocence,manifests the judicial human rights protection,is closely related to the burden of proof and standard of proof,and has sufficient basis in the current law in China.It is a generally applicable principle of criminal evidence law,but its application has certain conditions and requirements.The doubt of the fact means that the proof has not reached the degree of hard and sufficient evidence,and the charge should be judged in favor of the accused because of the existence of a reasonable doubt.In addition to the basic handling methods such as no punishment for doubtful cases,the negotiable judicial method can be applied under the restrictive conditions.Defensive facts,even if in doubt due to insufficient proof,should be judged by applying the principle of in dubio pro reo as long as they meet the preponderance of evidence standard.The principle of in dubio pro reo may also be conditionally applied to'correspondence offense','cases in which multiple acts lead to a single harmful consequence but the specific causal link is unclear',and procedural facts.At the same time,we should pay attention to the exceptions to the principle and accurately grasp its applicable conditions and methods in accordance with the law.In order to guide judicial operations,clearer judicial interpretations and case guidance should be made on certain controversial issues,and at the same time,the principle should be recognized as a basic principle of China's criminal procedure law and criminal evidence law.