The regional equity market has preliminarily established a dual-layer “regulatory chain-business chain” architecture under the guidance of the securities regulatory commission, achieving efficient supervision of market activities and execution of business operations. Market participants include enterprises, regulatory authorities, equity trading centers, and other stakeholders, each with different needs and expectations for data privacy and security. Additionally, the market data types and sources are diverse and heterogeneous, presenting significant challenges for multi-party data privacy protection. In response to issues such as regulatory oversight and data privacy protection under the dual-layer chain architecture of the regional equity market, this paper designs a privacy protection algorithm based on homomorphic encryption and zero-knowledge proofs. It also integrates privacy smart contracts designed for the cross-market interconnectivity and interoperability business processes in the regional equity market, enabling the coordinated execution and verification of privacy computations across on-chain and off-chain environments. This approach effectively protects private data while meeting the usage requirements of business scenarios.