Since the financial crisis in the United States broke out in 2008, the concept of shadow banking has begun to receive widespread attention. The potential risks of shadow banking have the impact on the financial market the focus of people's research. There are some similar places to commercial banks and commercial banks, which also have the function of currency creation, but the wide range of business scope of shadow banking, the depth of financial innovation makes the amount of money in the actual market far exceed the observation of the central bank, affecting the monetary policy Effectiveness. This article starts with the credit transmission mechanism in the theory of monetary policy transmission mechanism, analyzes the role of shadow banking in the credit market, and describes the concept and characteristics of shadow banking to grasp the overall form of shadow banking. Empirical analysis is mainly to establish a VAR model analysis of shadow banks' impact effects on bank credit, currency supply, and GDP, and verify the role of shadow banks in the process of credit transmission mechanism. Finally, according to the research results of the full text, this article gives suggestions from improving the regulatory system, expanding the scope of credit creation, and improving the credit transmission mechanism.