We study financing and information asymmetry issue in a two-echelon supply chain consisting of a commercial bank, a supplier and a retailer with capital constraint, in which the retailer can apply for loans from the commercial bank or apply for trade credit financing and guarantor credit financing from the supplier. The equilibrium shows that when bank credit finance is viable, the retailer decides whether to share information is neutral. When trade credit financing or guarantor credit financing is viable, the retailer shares information with the supplier. Blockchain technology provides capacity for the retailer to convey the downstream information to the supplier. The result also shows that when the guarantee ratio is relatively large, commercial bank tends to lower interest rate while the supplier is unwilling to provide GCF to the retailer. Finally, we also study the financing mode decision and demonstrate that a lower production cost promotes the supplier to provide TCF under information sharing. When there is no information sharing, the retailer’s optimal financing choice depends on the supplier’s estimation of market demand.