Abstract: Aiming at the issue of fairness in cloud storage integrity audit, a Cloud Storage Integrity Auditing Model Based on Consortium Blockchains (CSACB) is proposed. First of all, the model describes the composition of audit consortium (AC) by a tree structure, and uses the layer certificate chain (LCC) to identify and control the members of the alliance. Second, variable cloud storage auditing is supported by a two-chain form of integrity auditing chain and dynamic operating chain. Finally, the fair dynamic operation audit model is constructed by using the smart contract (SC) and the data block label index mechanism, and the results of theoretical analysis and experimental show that the model has obvious advantages in terms of security and performance.