As the existing micro-credential systems rely on centralized management model, the security of credentials cannot be guaranteed. To tackle with such problem, this study introduces blockchain technology into the architecture design of micro-credential systems, utilizing its distributed structure and technical characteristics (i.e., transparency and immutability). This study first illustrates the drawbacks of existing micro-credential systems, and introduces the basic concept of Blockchain ecosystem. Secondly, an architecture of Blockchain-based micro-credential system is designed and proposed in this research, to provide efficient and intuitive services related to micro-credentials. Finally, a prototype of the proposed system architecture is implemented, and evaluated in terms of performance and security. The experiment results show that the proposed approach in this study can be applied to Blockchain-based micro-credential system, to facilitate its design and implementation.