The utility model relates to an underground low-voltage branch cable connector assembly. The assembly comprises a base, T-shaped connectors, copper compression terminals and lock screws, the base is provided with a copper bar and copper rods, the copper rods are screwed on the copper bar, the connecting assembly of the copper bar and the copper rods is wrapped by insulating rubber, and the tops of the copper compression terminals are provided with screw holes; the T-shaped connectors are arranged on the copper rods wrapped by the insulating rubber, the copper compression terminals are plugged in the T-shaped connectors, the heads of the copper compression terminals are arranged over the copper rods, and are provided with positioning holes, and the positioning holes and the screw holes on the tops of the copper rods are fixed together by the lock screws. Compared with the prior art, the utility model has the following advantages: in a narrow underground entry, at most five branches (one trunk cable and four branches) can be connected; and in the narrow underground entry, the connected cables cannot be over-bent.