Prefabricated substation is composed of transformers, high-voltage switchgear and control equipment, low-voltage switchgear and control equipment, electric energy metering devices, corresponding internal connecting lines (cable busbars and others) and auxiliary equipment, etc., combined in one or more cabinet . It is especially suitable for the construction and transformation of urban network, which can go deep into the load center, improve the quality of power supply, and reduce loss. It has a series of advantages as high integration, small size, short power transmission cycle, flexible site selection, strong adaptability to the environment, convenient installation and safe operation and reliable, less investment cost and high efficiency.