pre branch cable is the cable that the factory prefabricates the branch line according to the user's design drawings when producing the main cable. The pre branching cable consists of four parts: 1. Trunk cable; 2. Branch line; 3 branch joint: 4 relevant accessories, and has three types: ordinary type, flame retardant type (Zr) and fire resistant type (NH). The utility model has the advantages of low water-proof and 6.0/0-kv branch power supply for high-rise buildings, convenient installation and maintenance of other power supply lines, and has the advantages of low water-proof and low rated power supply area for other buildings. The utility model has the advantages of low power supply area, low maintenance rate, etc. It is widely used in vertical power supply in electrical shafts of high and medium rise buildings, residential buildings, commercial buildings, hotels and hospitals. It is also suitable for power supply systems such as tunnels, airports, bridges and highways.