随着 AIGC 技术普及与短视频产业的爆发式增长，短视频二次创作已成为兼具文化传播价值与版权争议的核心议题。其创作形态从传统剪辑拼接向 AI “魔改”、模板化生成等多元演进，导致版权边界模糊与侵权认定困境。本文基于现行《著作权法》框架与司法实践案例，聚焦短视频二次创作的版权边界核心争议，系统分析合理使用认定、转换性使用本土化适用、平台责任划分等关键问题，梳理“三步检验法”“四要素法”在司法实践中的适用分歧，最终提出“类型化界定—分层化认定—协同化治理” 的侵权认定路径与制度完善建议，为平衡原创激励与创作自由、规范行业发展提供法学支撑。

With the popularization of AIGC technology and the explosive growth of the short-video industry, secondary creation in short videos has become a core issue involving both cultural communication value and copyright disputes. Its creative forms have evolved from traditional editing and montage to diversified modes such as AI “remix” and template-based generation, leading to blurred copyright boundaries and difficulties in infringement determination. Based on the current framework of the Copyright Law and judicial practice cases, this paper focuses on the core controversies over copyright boundaries of secondary creation in short videos, and systematically analyzes key issues including the identification of fair use, the localized application of transformative use, and the division of platform responsibilities. It also sorts out the divergences in the judicial application of the “three-step test” and the “four-factor test”. Finally, it proposes an infringement determination path and systematic improvement suggestions featuring “typed definition— hierarchical determination— collaborative governance”, so as to provide legal support for balancing original incentive and creative freedom and regulating the development of the industry.