Based on the "Plan for Optimizing the Business Environment in the 14th Five-Year Plan Period of Beijing", the evaluation index system of the business environment of small and medium-sized enterprises in Beijing was proposed. The relevant statistical data from 2017 to 2021 was used to empirically analyze the current situation of the business environment by using the entropy method. The results show that among the overall business environment, the market environment, legal environment, government service environment and humanistic environment for small and medium-sized enterprises in Beijing have been continuously improved. Second, the investment and trade environment is still unstable. Finally, from the four aspects of human capital, financial, investment and trade, and government "delegating-regulation-service ", suggestions for the optimization of the business environment of small and medium-sized enterprises in Beijing are put forward.