Abstract: The present disclosure relates to a searchable encrypted data sharing method and system based on blockchain and homomorphic encryption, which protects security of sensitive data on the blockchain and realizes searchable and homomorphic calculation of data ciphertext. According to the present disclosure, a data owner encrypts the generated sensitive data and the keywords extracted according to the data with his own key, and then sends the encrypted transaction information to the cloud server. The cloud server verifies the identity of the data owner. If the verification succeeds, the uploaded ciphertext data is stored on a local server, and a ciphertext index, keyword ciphertext and related evidences of the data storage are uploaded to an alliance chain. The alliance chain node verifies the consistency of the uploaded transaction information, and if the verification succeeds, the transaction information is recorded.