The adoption of cross-chain smart contract technology to address cross-chain data transactions has become a key means of achieving interoperability between different blockchain platforms. However, as this technology is increasingly applied in fields such as finance, issues related to inter-chain access control and data security are becoming more prominent. Therefore, this paper proposes a data privacy regulatory scheme based on cross-chain smart contracts. By registering cross-chain routes, it resolves the problem of identity authentication difficulties between heterogeneous chains. The design involves pre-exchanging public key information between local chains and regulatory chains to achieve unified encryption and decryption of inter-chain data. Through experimental testing and analysis, the feasibility of the proposed scheme is validated, demonstrating that it enables cross-chain data regulation while providing more secure data transmission compared to other systems.