Based on the data about sci-tech finance development and the listed small and medium-sized manufacturing enterprises in 2010-2017, the paper used the median effect test model to reveal the internal mechanism between sci-tech finance development and technological innovation of the small and medium-sized manufacturing enterprises and test the relationship between policy sci-tech finance and market sci-tech finance. The results shows that：①The substitution effect between policy sci-tech finance and market sci-tech finance slightly outweighs the complementary effect.②Commercial bank loans and venture capital slightly promote enterprise technological innovation. ③Fiscal investment in science and technology indirectly restrains the enterprise technological innovation by reducing R & D investment. ④Capital market financing not only directly restrains the enterprise technological innovation, but also indirectly restrains its technological innovation by reducing R & D investment.