With the rapid advancement of network technologies, blockchain, and cloud computing, secure data sharing has emerged as a critical challenge. Keys play a pivotal role in ensuring data security, yet traditional key management systems suffer from issues such as single points of failure, inefficient key distribution, and cumbersome key updates. Therefore, this paper designs a blockchain-based attribute-based encryption full life cycle key management scheme, which realizes the initialization of the system and the generation, storage, backup, recovery, update, loss and revocation of keys for ciphertext policy attribute-based encryption keys. Additionally, this paper incorporates secret sharing technology and introduces decentralized identity to enhance the overall degree of decentralization. Through comprehensive simulation tests and theoretical analysis, we demonstrate that the proposed solution achieves robust performance and high security.