Small and medium-sized enterprises are playing an important role in Chinese economic development. However, due to the lag in system construction, the scale of small and medium-sized enterprises is relatively small; many of these enterprises lack funds, and it is difficult to get loans. The financing difficulty of small and medium-sized enterprises always exists in China, which has become an important reason restricting their further development. In the past, smes used to borrow money from banks to finance their development. They have been borrowing from banks with their assets as collateral, but as the country has adopted a tight monetary policy, most of the loans applied for by smes have been rejected by banks. Private equity fund has the characteristics of low financing threshold and high added value of enterprises, helping many small and medium-sized enterprises to solve the capital problem, enabling them to develop and grow. In the process of private equity fund financing, the macro environment and micro factors bring huge risks to the whole financing process. Therefore, it is necessary to evaluate, analyze and control every risk that may cause financing failure in the financing process. This paper uses the method of literature review, qualitative and quantitative combination, through the construction of small and medium-sized enterprise private equity fund investment risk evaluation index system, from the micro and macro environment to evaluate and analyze the risk, for the analysis of small and medium-sized enterprises may face financing risk to provide effective avoidance measures.