Small business financing is accompanied by supply chain financial risks, and in-depth research on how to reduce supply chain risks is of great significance to the smooth financing of small and medium-sized enterprises. The characteristics of blockchain technology, such as distributed storage, open and transparent records and data sharing, help supply chain finance operation process transparency Research on the enabling mechanism of blockchain technology and identification of key risk parameters are of guiding significance to reduce the risk of supply chain finance system. This paper focuses on SMEs and commercial banks under the accounts receivable financing mode, constructs a game model of supply chain financial risk evolution before and after blockchain technology empowerment, analyzes the evolutionary equilibrium point of the two sides and its stability, and conducts a sensitivity analysis of the key parameters using Matlab, and finally compares the evolution trend before and after blockchain technology empowerment, so as to validate the degree of blockchain technology empowerment in reducing the risk of supply chain finance.