The purpose of introducing blockchain into electronic archives sharing and utilization is to break the information barrier between electronic archives sharing departments by relying on technologies such as smart contract and asymmetric encryption. Aiming at the problem of dynamic permission management in common access control methods, a new access control method based on smart contract under blockchain is proposed, which improves the intelligence level under blockchain technology. Firstly, the Internet attribute access control model based on smart contract is established. For the dynamic access of heterogeneous devices, the management contract, permission judgment contract and access control contract are designed; Secondly, the access object credit evaluation algorithm based on particle swarm optimization radial basis function (PSO-RBF) neural network is used to dynamically generate the access node credit threshold combined with the access policy, so as to realize the intelligent access right management method. Finally, combined with the above models and algorithms, the workflow of electronic archives sharing and utilization model of multi blockchain is constructed. The experimental results show that the timeconsuming of the process increases linearly with the number of continuous access to electronic archives blocks, and the secure access control of sharing and utilization is feasible, secure and effective.