Guided by the strategic goal of accelerating the construction of a strong science and technology（S&T）country, enhancing the overall effectiveness of the national innovation system（OENIS）has become one of the main concerns in the development of China's S&T innovation. This study presents the idea connotation of the OENIS from the meaning of effectiveness and overall effectiveness, based on the era background of Chinese path to modernization the theory of the national innovation system. And this study constructs an analytical framework for the OENIS from three dimensions: subject effectiveness, institutional effect, and spatial utility. Then proposes practical insights from three aspects: enhancing the benefits and capabilities of diversified innovation entities, stimulating the institutional effect of scientific and technological innovation, and enhancing the spatial utility of innovation fields. This work is highly valuable as it highlights the need of improving the OENIS in light of China's modernization strategy and offers theoretical justifications for achieving high-level scientific and technological self-reliance and constructing a robust scientific and technological nation.