“一事不再罚”是行政处罚的重要原则。《行政处罚法》第29条规定“一事不再罚”的前提是同一个违法行为。但是我国的法规范中，并没有对同一违法行为的界定，学界对于如何确定同一违法行为存在不同观点，实践中对于同一违法行为的界定也存在争议，导致“一事不再罚”原则的适用存在困境。本文主要想解决的问题是如何界定“一事不再罚”原则中的同一违法行为，尤其是一个自然行为违反多个法律规范，如何适用“一事不再罚”原则。首先，通过总结司法实践中关于同一违法行为界定的不同判决，发现主要存在三个困境：一是自然行为和违法行为辨别不清；二是法条竞合和想象竞合适用混乱；三是行政处罚和刑事处罚关系存疑。其次，针对司法实践中的困境，主要分析学者对于三个困境的争议，通过比较不同学说观点，发现行政法益是解决争议的关键。然后，主要讨论行政法益的根本性地位，分析如何从行政法益的角度解决上述提到的三个困境。第一，是否违反法律规范、是否侵害行政法益是区分自然行为和违法行为的重要标志；第二，识别违法行为侵害的行政法益数量，有利于辨清法条竞合和想象竞合；第三，本文认为行政法益和刑事法益主要是量的区别，行政处罚和刑事处罚可以折抵。最后，以自然行为数量、违反法律规范数量、侵犯法益数量为维度进行分类，对违法行为进行类型化讨论，从而确定同一违法行为的界定标准，为“一事不再罚”原则适用提供借鉴。当违反一个法律规范侵害一种法益时，有争议的主要是继续性违法行为和连续性违法行为两种情况；当违反多个法律规范侵害一种法益时，主要是法条竞合情形，本文认为“择一重罚”的基础上，不同种类行政处罚可以并罚；当一个自然行为侵害多种法益时，侵害多个法益构成多个违法行为，不适用“一事不再罚”原则，但也需要考虑法益之间的重合性、包容性。
"No Double Jeopardy" is an important principle in administrative penalty. Article 29 of the Administrative Penalty Law of China stipulates that the premise of "No Double Jeopardy" is the same illegal act. But there is no definition of the same illegal act in our country‘s legal norms, the academic community has different views on how to determine the same illegal act, and the definition of the same illegal act is also controversial in practice, which leads to the dilemma in the application of the principle of "No Double Jeopardy".The main problem to be solved in this paper is how to define the same illegal act in the principle of "No Double Jeopardy", especially how to apply the principle of "No Double Jeopardy" when a natural act violates multiple legal norms. First of all, by summarizing the different judgments on the definition of the same illegal act in judicial practice, it is found that there are three main dilemmas: first, the distinction between natural act and illegal act is unclear; second, the application of law article concurrence and imaginary concurrence is confused; and third, the relationship between administrative penalty and criminal penalty is doubtful. Secondly, in view of the dilemmas in judicial practice, the main analysis of scholars‘ disputes over the three dilemmas, through the comparison of different theories and viewpoints, the administrative legal interest is found to be the key to resolving disputes. Then, it mainly discusses the fundamental position of administrative legal interests, and analyzes how to solve the three dilemmas mentioned above from the Angle of administrative legal interests. First, whether it violates legal norms or infringes administrative legal interests is an important sign to distinguish natural acts from illegal acts. Second, identifying the amount of administrative legal interests infringed by illegal acts is conducive to distinguishing the concurrence of articles of law and the imaginative concurrence ; Thirdly, this paper holds that administrative legal interest and criminal legal interest are mainly quantitative differences, and administrative penalty and criminal penalty can be offset. Finally, this paper classifies the number of natural acts, the number of violations of legal norms, and the number of violations of legal interests, and discusses the types of illegal acts, so as to determine the definition standard of the same illegal act, and provide reference for the application of the principle of "No Double Jeopardy". When one legal norm is violated and one legal interest is infringed, there are two kinds of controversial cases: continuous violation and continuous violation. When multiple legal norms are violated and one legal interest is infringed, it is mainly the case of concurrence of legal articles. This paper holds that different kinds of administrative penalties can be combined on the basis of "Higher Fine Chosen"; When there is only one natural act but multiple legal interests are infringed, the infringement of multiple legal interests constitutes multiple illegal acts, and the principle of "No Double Jeopardy" is not applicable, but the coincidence and inclusiveness of legal interests should also be considered.
