For realizing the real-time peer-to-peer communication and interoperability between the distributed control application related sites Smart Terminal Units (STUs), the GOOSE (Generic Object—Oriented Substation Event) could be used to transfer real-time data and commands among STUs. Based on the analysis of the existing mapping mode of GOOSE, a GOOSE mapped to TCP transmission mechanism (GOOSE over TCP) is proposed. The implementation method and the improvement measures to increasing the real-time of GOOSE over TCP are given. The main factors that affecting transmission delay are analyzed. In the harsh environment which is full of the burst network message, after taking the improvement measures, the maximum transmission delay of GOOSE over TCP communication is about 2.4 ms, the average delay is about 1.3 ms, which could satisfy the needs of distributed control applications in distribution network. This work is supported by National High-tech R & D Program of China (No. 2015AA050202).