Abstract: With the continuous advancement of electricity market reform in China, communication security in electricity spot systems has increasingly become a key factor affecting system stability and reliability. To effectively address security risks between applications and data services, this paper proposes a secure communication architecture for electricity spot systems based on registration service and message bus. By introducing a security registration service and message bus service, the architecture achieves application identity authentication, encrypted data transmission, communication link isolation, and data integrity verification. While ensuring communication security, it also supports system scalability and maintainability, demonstrating strong potential for broader application.