Policy innovation is crucial for achieving the modernization of national governance capabilities. Existing research，dominated by policy diffusion theory，primarily focuses on the dissemination and adoption of policy innovation，often neglecting the study of government behavior post-policy adoption. In reality，government behavior following the adoption of policy innovation is closely related to the performance of the innovation. The theory of policy reinvention，through the study of policy texts，reveals the mechanisms of government behavior after the adoption of policy innovation. Therefore，the evolution of policy reinvention theory is particularly important for a comprehensive understanding of the policy innovation process. Policy reinvention refers to the process by which a primary-level government refines，updates，or assimilates the prototype policies of higher-level or peer governments and enacts corresponding public policies within its jurisdiction. Most existing studies regard “reinvention” as a stage of “policy diffusion”，resulting in overlaps and intersections in conceptual definitions and process mechanisms. This study argues that policy reinvention is fundamentally different from policy diffusion in terms of process mechanisms. Therefore，this paper clarifies the conceptual connotation of policy reinvention through a comparative analysis of concepts; constructs a comprehensive model of the policy reinvention generation process by reviewing the research on the policy reinvention process; and explains the generation mechanism of policy reinvention by combining the influencing factors of reinvention. The study finds that during the downward diffusion of policies，the tension caused by localization resistance serves as a trigger for reinvention. The core of reinvention is the learning mechanism，where different learning pathways produce four types of knowledge: empathic，conceptual，negotiated，and technical. Factors such as policy dimensions，reinventor dimensions，and environmental dimensions influence the generation and degree of reinvention. Issues such as the effect of time and geographical influence remain controversial. Policy reinvention provides a unique perspective for analyzing local government innovation. Future research can continue to deepen the distinction between policy reinvention and related concepts，exploring the generation mechanisms in different contexts to enrich the theory of policy innovation research.

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