Abstract:     In recent years, against the backdrop of increasing uncertainties in the external environment, such as the reconstruction of the global value chain, the intensified international scientific and technological competition and the vision of a "zero-carbon future", improving the national innovation system (NIS) and enhancing the overall effectiveness of the NIS have increasingly become a strong support for achieving the goals of stable economic operation and realizing carbon peak and carbon neutrality. The development of scientific and technological innovation is inseparable from the support of finance. As a direct "supplier" for innovation, sci-tech finance has become the fundamental guarantee for innovation subjects to break through the "bottleneck" of key core technologies and guide innovation subjects to get closer to the national development strategy. However, it remains to be unclear how sci-tech finance can enhance the innovation ability, improve the efficiency of the innovation process, so as to help improve the overall effectiveness of the NIS. Therefore, this paper is devoted to discussing how to improve the safeguard measures for scientific and technological innovation, and to break the financial barriers in the innovation process, thus giving full play to the role of sci-tech finance to improve the overall effectiveness of the NIS. This paper firstly explains the relationship between the overall effectiveness of the NIS and sci-tech finance. It is proposed that the improvement of the overall effectiveness of the NIS in the new era requires taking into account both the capacity and efficiency of the NIS, paying attention to the coordination of various functions and the complementary sharing of resources, so as to synergize the result performance and process performance. This means that while focusing on high-quality output, the efficient operation of the innovation process should also be concerned. During this process, the strengthening of capacity and the improvement of efficiency are inseparable from the diversified, multi-dimensional and multi-level support of sci-tech finance.Secondly, this paper summarizes and analyzes the overall influence mechanism of sci-tech finance for improving the overall effectiveness of the NIS from the macro level, including the financial support, information management, risk management and control. First, as for the function of financial support, sci-tech finance can guide financial resources and social capital to gather around various innovation subjects, stimulate the innovation enthusiasm, and promote the collaboration between them, so as to support innovation subjects to produce high-quality achievements and improve the efficiency of achievement transformation. Second, sci-tech finance can effectively alleviate the problem of information asymmetry between the innovation subjects and external investors, guide the capital to incline to the actors with innovation ability, so as to give full play to the ability of innovation subjects while improving the efficiency of resource utilization. Third, the interaction and coordination among multi-level and multi-faceted financial entities can also reduce the adverse consequences of various risks to a certain extent, optimize the risk-benefit structure, so as to provide a harmonious environment for the overall effectiveness improvement of the NIS.Then, by constructing a sci-tech finance support framework based on the structure of the effectiveness of the NIS, this paper deeply analyzes the specific support path of sci-tech finance to the improvement of the capacity and efficiency of the NIS from the perspective of innovation chain. It is found that the effectiveness of the NIS covers the ability of basic research, technological innovation, market development, technological iteration and social service, as well as the efficiencies of technological transformation, commercial transformation, technological development and sustainable development across different activity processes. On the basis of providing financial guarantee and regulatory governance for different innovation activities, sci-tech finance smooths and covers the entire process of improving the overall effectiveness of the NIS, effectively promotes the coordination of functions and the complementary sharing of resources, thus continuously improving the overall innovation capacity and efficiency.Finally, based on the above analysis and realistic background, this paper puts forward the following policy insights. (1) Improve both the quantity and quality of sci-tech finance for innovative enterprises, so as to encourage enterprises to become the main body to promote the overall effectiveness improvement of the NIS. (2) Promote the support of sci-tech to the improvement of the NIS effectiveness with the help of Fintech. (3) Build a sci-tech financial ecosystem that is compatible with the overall effectiveness improvement of the NIS. This paper provides theoretical basis and practical enlightenment for promoting the construction of NIS and improving the overall effectiveness of the NIS from the perspective of finance.

Key words: sci-tech finance, national innovation system, overall effectiveness