Abstract: Supported by multiple connection modes and communication protocols, external interactive interface server provides the information interaction function between local railway administration and outside units, meanwhile, implements the function of TDCS-CTC platform interaction and train diagram query. In order to improve the compatibility, scalability and data processing capability of the interface server, the three tier software architecture with user management layer, information processing layer and data management layer was designed and implemented. The internal data flow of the interface server used TDCS protocol uniformly, and the corresponding processing logic was selected for different protocol versions. With the help of multi-destination forwarding, high efficient data caching and information package algorithm in sliding window model, interface server can meet the production demands with high deployment flexibility, running stability, security and efficiency.