A
distribution transformer prefabricated connection line with a closed insulating cover comprises a wire pole, the wire pole is provided with a drop-type switch, a
lightning arrester and a
transformer, the drop-type switch, the
lightning arrester and the
transformer are connected through a connection line body. The
distribution transformer prefabricated connection line is characterized in that the connection line body comprises a main line
copper tube, and a first plastic
copper line penetrates into a main line
copper tube, an electrical inspection grounding ring is connected with the side wall of the main line copper tube and comprises a grounding ring copper tube, the outer wall of the grounding ring copper tube and the outer wall of the main line copper tube are coated with a main line
silicone rubber insulating layer, a bare electrical inspection grounding point is arranged on the lower portion of the electrical inspection grounding ring, one end of the first plastic copper line is connected with a first connection terminal which is connected with the drop-type switch, the outer wall of the portion, between the first connection terminal and the main line copper tube, of the first plastic copper line is coated with a first
silicone rubber insulating layer, the other end of the first plastic copper line is connected with a second connection terminal which is connected with the
transformer, the outer wall of the portion, between the second connection terminal and the main line copper tube, of the first plastic copper line is coated with a second
silicone rubber insulating layer, the portion, located in the main line copper tube, of the first plastic copper line is a line core with a plastic wrapper stripped, the line core is connected with a core of a third plastic copper line, and the outer wall of the third plastic copper line is coated with a third
silicone rubber insulating layer.