The classification of box-type substations (commonly known as "European box-type substations") is mainly based on the type of high-voltage switchgear, the shell structure, and the internal layout. The most common classification method is based on the wiring scheme on the high-voltage side, which is divided into two categories: terminal type and ring network type. The terminal type has a simple structure and only has a single power supply line; the ring network type is equipped with multiple circuits of incoming and outgoing lines, which can achieve flexible power supply network connection. According to the shell material, it can be divided into metal (such as steel plate, aluminum alloy) and non-metal (such as glass fiber reinforced cement, composite board), respectively meeting different requirements such as strength, corrosion resistance, and aesthetics. In addition, according to the spatial layout of the internal high-voltage switchgear, transformer, and low-voltage distribution unit, it can be divided into "目" type (three in parallel) and "品" type (transformer is placed at the end) structures, which directly affects the overall size, heat dissipation performance, and operation and maintenance convenience of the box-type substation.