A pouring bus duct and intensive bus duct conversion joint comprises a shell, a sealing plate, side plates, a conversion joint baffle plate, an end part baffle plate, an intermediate transition welding busbar, a pouring bus, an intensive bus, a pouring material and round nuts, wherein each sealing plate sequentially penetrates through a sealing plate hole and a sealing plate connection hole by a fastening piece to achieve fixed connection with two ends of the shell, the side plates are symmetrically arranged at two sides of an outer wall of the shell, the conversion joint baffle plate is arranged on an inner wall of one side of the shell, the side plates, the shell and the conversion joint baffle plate sequentially penetrate through side plate holes, side plate connection holes and a conversion joint baffle plate hole to achieve fixed connection by a fastening piece, the end part baffle plate is arranged at one side of the shell, the four round nuts are arranged in the shell, and the pouring material is filled in the shell. The pouring bus duct and intensive bus duct conversion joint is simple in structure, small in appearance structure and high in safety and is convenient to fabricate, standard of production, site measurement and installation can be achieved.