Recently, blockchain has been a disruptive technology for many systems, such as fmance, e-health, supply-chain, and etc. Secure access to blockchain is the grand challenge for many systems. Key management is one of challenges to ensure secure access to blockchain. In this paper, we propose a framework for secure accessing to blockchain via multi-factor authentication. We combine both biometric and password authentications to secure private keys of users. The framework contains a secure device which has a biometric sensor to ensure secure access to private keys that extends the usability for secure accessing to blockchain.