Small and medium-sized enterprises (SMEs) are an important part of relieving the pressure of social employment and increasing the development and vitality of the world economy. However, the disadvantages of SMEs in terms of their scale and normality have led to problems such as difficulties in financing during their development, which have increased the difficulty of their development and growth. To address this social reality, it is urgent to establish a perfect credit guarantee system for SMEs. With the continuous development of China's information technology, financial institutions are also transforming, providing new ideas for the improvement of the credit guarantee system for SMEs. Over the years, the implementation of "blockchain + credit guarantee" has brought unprecedented revolutionary impact to the financial industry. It has not only greatly expanded the application scope of blockchain technology, but also greatly improved the credit guarantee mechanism for SMEs, greatly enhanced their financing efficiency, and effectively reduced their risks, laying a solid foundation for their long-term stable development. To better support the development of SMEs, we should accelerate the digital transformation to realize the effective allocation of financial resources and enhance the market competitiveness of SMEs, to better meet their economic and social development needs.