Abstract: Identifying the endogenous drivers behind the transformation of small and medium-sized enterprises toward“Specialized, Refined, Distinctive and Innovative”(SRDI) enterprises is of profound strategic significance for building a self-sufficient and secure modern industrial system. Based on the 86 policy texts on the cultivation of specialized, refined, unique, and innovative enterprises issued by various central ministries and commissions from 2011 to 2024, this study integrates NVivo12 high-frequency word statistics, Dynamic Topic Model (DTM), and Grounded Theory research method to reveal the deep mechanism of gradient cultivation policies driving the endogenous development of the specialized, refined, unique, and innovative enterprises. The research findings show that the policy system exhibits a dynamic evolutionary characteristic of“technology incubation - capability enhancement - ecosystem empowerment”, precisely adapting to the gradient capability needs of the specialized, refined, unique, and innovative enterprises. Through a transmission path of“target setting (guiding role) - resource adaptation (supporting role) - motivation activation (promoting role)”, policy instruments drive the enterprises to form a dynamic mechanism for the development of specialized, refined, unique, and innovative enterprises, which involves the progressive coupling and cyclic interaction of four driving elements: human capital, technological innovation, production methods, and brand market. Further analysis reveals that significant differences in this dynamic mechanism exist among the three types of gradient enterprises: specialized, refined, unique, and innovative enterprises. Innovative enterprises exhibit an“exogenous dependency”pattern; specialized, refined, unique, and innovative SMEs demonstrate a“conduction block”pattern; and specialized, refined, unique, and innovative“little giant”enterprises show a“feedback loop”pattern. In light of this, it is recommended that future policies anchor around the endogenous development needs of enterprises, precisely implement strategies in conjunction with endogenous driving factors and their synergistic mechanisms, and focus on combining gradient design with dynamic governance to enhance the effectiveness of policy implementation.

Key words: specialized,refined,distinctive and innovative enterprises, gradient cultivation, endogenous development dynamics, policy text analysis, dynamic topic model