In view of the low intelligence level of GIS equipment in internal substations, the technology of intelligent GIS based on the integrated on-site control unit is proposed. Firstly, the status of GIS equipment is analyzed, while the preliminary researches on intellectualization are combed. Then, the functional principles of this technology are researched, including motor drive control of circuit breaker, electronic transformer (ECT/EVT) sampling, tripping/closing phase control, real-time monitoring sensors implementation, bay measurement control, disturbance analysis and video auxiliary control. Finally, the installation and operation scheme of this technology are researched, including physical fusion installation scheme and equipment configuration scheme. The proposed technology could improve the intelligence level of GIS equipment, decreasing the complexity of equipment configuration and maintenance. This work is supported by Scientific and Technological Achievements Transformation Fund Project of Jiangsu Province (No. BA2016057).