近年来，一些涉及正当防卫的案件在社会上受到广泛关注，一直以来被诟病的“僵尸条款”也逐渐开始被公众所熟知，这很大程度上归功于立法的进步、司法机关理论更新和人民群众法律意识的提升。但尽管如此，正当防卫在实务中的适用仍不理想，尤其是在正当防卫与防卫过当之间的区分中，往往就会因过度扩大防卫过当的适用范围而将案件认定为防卫过当。实务状况随着社会发展千变万化，理论需要随之进行相应的改变才能更好的指导实践，因此对认定防卫过当这类偏实务问题的研究不能只集中在法理上的研究。基于此原因，文章从司法案例考察这一角度为重点展开对防卫过当的认定的研究。具体通过理论的梳理确定研究内容和设计研究变量从而指导司法考察，进而通过司法考察验证理论、发现问题以反馈给理论，通过理论梳理和司法考察总结出可以指导实践相关标准，并为立法的完善提出一些建议。

文章从“明显超过”、“重大损害”和“必要限度”三个角度展开了防卫过当认定的理论梳理。对认定“明显超过”中如何进行量化比较的方法以及“明显超过”与“必要限度”的关系进行了讨论；梳理了什么是“重大损害”以及“重大损害”在认定防卫过当时的地位；对理论界关于必要限度的四种主要学说进行了分析整理。同样也从“明显超过”、“重大损害”和“必要限度”三个角度进行了司法考察。经过实证考察，发现司法实践中在认定防卫过当时标准不一，但唯结果论的倾向性已经明显减小；对于必要限度是否“明显超过”的判断并非将单一要素量化比较，而是多种因素的综合性判断；在考察与“必要限度”相关的因素上，发现实践认为防卫行为并非是面对不法侵害的最后手段以及不法侵害对防卫人心理的影响也是判断“必要限度”的重要因素。基于考察结果和以往的学者的研究成果，文章从“明显超过”、“重大损害”和“必要限度”三个方面对防卫过当的认定标准予以总结。“明显超过”的认定标准为“是否超过防卫的需要”、“对比项之间是否相适应”两点；“重大损害”的认定标准为“相当于一人重伤”的损害后果；“必要限度”的认定标准为“以不法侵害的强度确定防卫所需强度”、“以不法侵害的紧迫程度确定防卫具有必要性”、“以被不法侵害的法益判断防卫的合理范围”三个。

In recent years, some cases involving justifiable defense have received widespread attention in the society, and the “zombie clause” that has been criticized has gradually become well known to the public. It due to the improvement of legislation, the update of judicial theory and the promotion of the legal awareness of people. However, the application of justifiable defense system is still not ideal in practice, especially in the distinction between justifiable defense and excessive defense, cases are often deemed to be excessive defense due to excessively expand the scope of application of excessive defense. The actual situation changes with the development of society, and the theory needs to be changed accordingly to better guide the practice. Therefore, the study of such practical problems as excessive defense cannot be focused solely on the study of jurisprudence. Based on this reason, this article will focus on the investigation of the determination of excessive defense from the perspective of judicial case investigation. Defining the meaning of legitimate defense, identifying research content and designing research variables to guide judicial investigations. then, verifying the theory by study case and finding problems to feed back to the theory, we conclude that relevant standards through theoretical review and judicial investigation and guidelines can be used to guide practice and put forward some suggestions for the improvement of legislation.

This paper makes a theoretical analysis of the identification of excessive defense from the three angles of "obvious excess", "significant damage" and "necessary limit". We discussed the methods of quantifying comparison in the determination of "apparently exceeding" and the relationship between "obviously exceeding" and "necessary limit", sorted out what is "major damage" and the status of "major damage" in judging the "necessary limit", and analyzed the four main theories of the necessary limit in the law academic circle. Judicial investigations have also been conducted from the perspectives of "apparently exceeding", "significant damage" and "necessary limits". After empirical investigation, it is found that there are different standards for determining excessive defense in judicial practice, but the tendency of result-only theory has been significantly reduced. The judgment that whether the necessary limit is "significantly exceeded" is not the quantitative comparison of single factor but the comprehensive judgment of multiple factors. The standard for evaluating "significant damage" in practice uses "equivalent to a serious injury" as the starting point for determination generally. In the investigation of the factors affecting the "necessary limit", it is found that defensive behavior is not the last resort to face unlawful infringement and the impact of unlawful infringement on the psychology of defenders is also an important factor in judging the "necessary limit". Based on the investigation results and the research results of previous scholars, his article summarizes the criteria for the identification of excessive defense from three aspects: "obviously exceeded", "significant damage" and "necessary limit". The criteria for determining "obviously exceeding" are "whether it exceeds the need of defense" and "whether the comparison items are compatible". The criterion for determining "significant damage" is the damage consequence "equivalent to serious injury of one person". The identification criteria of "necessary limit" include "judging the strength required for defense by the intensity of unlawful infringement", "judging the necessity of defense by the urgency of unlawful infringement", and "judging the reasonable scope of defense by the infringed legal interests".