Abstract: With the rapid growth of various ocean observation data, the problems of data inconsistency and non-traceability in data transmission, as well as security and trust issues in data sharing have become increasingly prominent. In response to the above problems, a blockchain-based ocean observation data transmission and sharing scheme is proposed. The scheme utilized the autonomy and non-tampering characteristics of blockchain, as well as technologies such as smart contract, digital signature and digital envelope to build an ocean observation data transmission consortium chain and a shared consortium chain based on cloud storage and blockchain network. The design of the new data transmission scheme, secure data sharing access mechanism and incentive mechanism provides a solution to promote the efficient and high-quality transmission and the safe and honest sharing of national ocean observation data.