Small and medium enterprises (SMEs) play an important role in promoting the national economy and providing employment opportunities. E-commerce platforms may facilitate transactions between these enterprises. However, transactions on the e-commerce platform are non-face-to-face, strongly virtual, and variable, resulting in SMEs often facing moral hazards and opportunistic behaviors. Blockchain is a distributed ledger consisting of an encryption algorithm, consensus mechanism, and smart contracts, having the characteristics of authenticity, security, transparency, and unforgeability. Thus, the problems faced by SMEs can be resolved by combining e-commerce platforms and blockchain technology. In this study, we first provide a conceptual framework for blockchain-supported e-commerce platforms for SMEs. Second, based on this conceptual framework, we build a total business architecture. Finally, we propose three key applications to illustrate how the platform facilitates SMEs in solving financing and trading problems. This study provides significant guidance for the operation and management of blockchain-supported e-commerce platforms for these enterprises.