The invention provides a two-circuit drill-through steel pipe rod and a power transmission system. The two-circuit drill-through steel pipe rod includes a rod body, a ground wire cross arm, an upper layer cross arm and a lower layer cross arm are sequentially arranged on the rod body from top to bottom in parallel, wherein middle layer guide lines and lower layer guide lines of a conventional two-circuit steel pipe rod are arranged horizontally on the lower layer cross arm; an upper layer guide line is disposed on the side of a non-drill-through line of the upper layer cross arm, and a groundwire and an upper layer guide line are horizontally arranged on the side of a drill-through line; a ground wire is arranged on the side of a non-drill-through line of the ground wire cross arm, and noground wire is arranged on the side of the drill-through line; and the guide lines of each layer communicate directly through jumpers, the optical fiber composite overhead ground wires communicate through optical fiber composite overhead ground wire leads, only a middle layer guide line cross arm is eliminated and an upper layer guide line cross arm and a lower layer guide line cross arm are lengthened on the conventional two-circuit steel pipe rod, the guide lines are changed from original vertical arrangement to the triangular arrangement, and the optical fiber composite overhead ground wire is arranged on the upper layer guide line cross arm through the drill-through line, so that the height of a drill-through line circuit is reduced, the optical fiber composite overhead ground wires (OPGW cables) are guaranteed to be continuous, and lightning protection of the drill-through line guide lines is provided by a drilled-through circuit.