In order to alleviate the increasingly serious problem of wind, solar and hydro power curtailments, the State Grid Corporation of China organized the surplus renewable energy inter-regional spot market to promote renewable energy consumption in large region by using market mechanism. This paper designs the overall functional framework of the surplus renewable energy inter-regional spot market operation support system for sending end grid, describes the relationship between State Grid Dispatch Control Center’s spot market trading platform and schedule system, analyzes the implementation technology of the core functions such as transaction security check and market clearing rule library, and develops the surplus renewable energy inter-regional spot market operation support system for sending end grid to coordinate the operation of State Grid Dispatch Control Center’s spot market trading platform. The operation support system has been put into operation in Gansu, Ningxia and many other provinces, which provides a comprehensive technical support for the sending end grid to participate in the surplus renewable inter-regional spot market and enhances the level of inter-regional renewable energy consumption and resource allocation capabilities. This work is supported by National Key Research and Development Program of China (No. 2016YFB0900502).