There are certain dissimilarities in the operation process in different capital constrained supply chain, and this will produce different angles of effect on the financing process of SMEs. Supply chain financing mode takes the trade situation of all enterprises in the supply chain as the basis, and the credit index of the core enterprises as the key point in order to provide help for the financing process of SMEs in the supply chain. This research firstly combines the specific definition of supply chain financing mode as well as the main financing method for specific research, introducing two kinds of financing methods in the supply chain respectively. And discusses the financing mode of different capital constrained SMEs specifically. Secondly, the financing methods based on supply chain finance have been explored effectively in order to conduct effective construction of the mode structure. And after that the subjects providing the capital supply, payment and settlement services have been further explored, making the inner relationship between the enterprises and the banks in the supply chain financing mode effective clear. Finally, two aspects including supply chain finance and traditional financing mode ratio and combinatorial optimization of capital constrained supply chain have been studied concretely, and in which the superiority of supply chain financing mode has been fully embodied.