Abstract: The complicated domestic and international situation after the COVID-19 epidemic has put forward new requirements for China's regional innovation and development. However, the main paradigm of regional innovation research in China is still the traditional regional innovation system theory, which pays insufficient attention to "knowledge", the core resource of regional innovation, and urgently needs new theoretical methods and policy tools. This paper introduces the basic theory of Regional Knowledge Base, which has been widely concerned in the West in recent years, and its emphasis on regional knowledge differentiation and dynamic evolution has important reference significance for China. Firstly, this paper defines the connotation of Regional Knowledge Base, which is the accumulation of knowledge acquired in a region's long-term historical evolution. Its unique scale, structure and quality characteristics determine the core competitive advantage of regional innovation, and also profoundly affect the track direction of regional technological development in the future. Secondly, the paper reviews the formation process of the basic theory of regional knowledge, divides it into two periods: 1.0 and 2.0, and summarizes the theoretical viewpoints and problems in different periods respectively.Thirdly, the paper summarizes the research on the multi-dimensional characteristics of regional knowledge base from three aspects: scale, structure and quality, focusing on analyzing the characteristics of regional knowledge base from the perspectives of diversity, relevance, complexity and originality. This paper introduces the dynamic perspective of evolutionary economic geography, and analyzes the dynamics of the evolution of regional knowledge base. Through literature review, this paper points out that technology association and regional institution are the main driving forces of regional knowledge evolution, and discusses the connotation and mechanism of technology association and regional institution respectively, with emphasis on the important role of regional institution in changing the path of knowledge evolution after China's reform and opening up.Then, the evolution path of regional knowledge base is analyzed, which is summarized as a complex process of "path dependence-lock in-path breakthrough". The process of knowledge creation and dissemination is influenced by path dependence, and the mechanism of path dependence mainly includes dependence on initial opportunity events, related diversified development, scale effect, irreversibility of investment and so on. Long-term path dependence may lead to the locked technical track of the region, which leads to stagnation and recession. When the path lock-in seriously hinders the regional knowledge renewal and even leads to the regional decline, the region needs to evolve new industries or knowledge group so as to move towards a new development track, which is called path breakthrough. Path breakthrough can transform existing industries by creating new path locally, improving the diversity and heterogeneity of knowledge structure, injecting new technologies or deriving from existing industries to related new industries, and introducing new industries and new knowledge from outside regions. Finally, the paper discusses how to use the theory of regional knowledge base to guide the formulation of China's regional innovation policy, especially to strengthen the cultivation of regional knowledge base, optimize the technical structure of local technology library and form local core competitive advantage.