Renewable energy not only has the advantages of low-carbon and cyclic renewable, but also has the disadvantages of high cost, low efficiency, and high investment risk. Therefore, broadening its financing channels and controlling risks have become key issues in the development of the renewable energy industry. In addition to traditional financing such as bank credit, the renewable energy industry can also use the carbon finance market for financing. However, for renewable energy companies, especially small and medium-sized enterprises, the existing carbon trading model is not conducive to their financing development. This article first analyses China's renewable energy financing system. Then, from the aspects of product and trading mechanism, we analyse the operation mechanism of carbon financial market. Finally, it analyses the product features and operating modes of related companies, such as high-emission companies and financial institutions. The article classifies renewable energy companies according to their size. Analyse the characteristics of enterprises of different sizes, and determine the corresponding financing model according to their characteristics. Large companies can use government special funds, clean development mechanisms, and carbon trading markets for financing. Due to its own scale defects, the above financing methods are not suitable for SMEs. This article has designed a financing model for tripartite participation based on carbon trading platform and green finance.