Prefabricated building block with distribution box structure

The utility model belongs to the field of building construction, and particularly relates to a prefabricated building block with a distribution box structure, which comprises a building block body and a distribution box embedded on the building block body, the upper side and the lower side of the building block body are respectively provided with a first groove connected to the side wall of the distribution box, and the left side and the right side of the building block body are respectively provided with a second groove. At least one inner supporting assembly is arranged in an inner cavity of the distribution box, each inner supporting assembly comprises a screw transversely arranged in the inner cavity of the distribution box, a first ejector block in threaded connection with the left end of the screw and a second ejector block in threaded connection with the right end of the screw, the first ejector blocks abut against the inner wall of the left side of the inner cavity of the distribution box, and the sec