Abstract:With the popularity of low carbon energy conservation and environmental protection consciousness, to save land resource, reduce the substation area of land expropriation, P- reinstalled substations is becoming more and more widely in the application of power grid. But prefabrication substation has not been used in metro power supply system. This article introduces the concept, classification, development and research status of the preinstalled substations. It also summarized the advantages and disadvantages of preinstalled substations . Compared with conventional substation, preinstalled substations is analyzed and summarized in the aspect of technology, economy, construction and operation management. It not yet extracted the valuable experience and conclusion, but also provided the referential suggestions for engineering construction investment. Based the differences between the subway power supply system and the power system, the preinstalled substations is a big plus.. Based on the special geological conditions of Guizhou province and the position of the main power station along the metro lines, the solution of use preinstalled substation for the current Guiyang problems existing in the process was constructed. It pointed out some dos and don’ts on the process of the preinstalled substations building in metro power supply system.