After 20 years of rapid development，China’s multi-level capital market system has made tremendous progress，and it has been a powerful impetus for sustainable and stable development. As China’s dynamic and creative enterprises，small and medium-sized S&T enterprises has been got strong support in their development process. The Third Plenary Session of eighteenth Congress of CPC proposed “multi-level capital market system”，Under this circumstance，it’s meaningful to discuss the contribution of capital market to small and medium-sized S&T enterprises’ development. This paper discusses the characteristics and status of small and medium-sized S&T enterprises，and then focuses on the capital market’s supporting methods for small and medium-sized S&T enterprises. Secondly，different methods for different stages of small and medium-sized S&T enterprises’ development are discussed in the different capital markets，including the stock market，the OTC market，the bond market and the investment funds market. The paper also sets some examples to prove the necessities for the roles of capital market. Finally，it provides some policy suggestions for the multi-level capital market system.