In terms of the wide source, large dynamics, and distributed management characteristics of big data resources, the current mainstream centralized access control mechanisms have shortcomings, such as low efficiency, insufficient flexibility, and poor scalability. Therefore, this study proposes a blockchain-based big data access control mechanism based on the ABAC model. First, in this paper, the fundamental principle of blockchain technology is described and the attribute-based access control model is formalized. Then, big data access control architecture is presented based on blockchain technology, and the basic framework and flow of access control are analyzed. At the same time, to ensure the access control information is tamper-resistant, auditability, and verifiability, the transaction-based access control policy and entity attribute information management methods are also described in detail. In addition, a smart contract-based access control method is used to implement user-driven, transparent, dynamic, and automated access control for big data resources. Finally, simulation experiments validate the effectiveness of this mechanism, and then the views presented in this paper are summarized and prospected.