The invention discloses a secondary short circuiting line for a CT and a PT. The secondary short circuiting line comprises a first clamp, a second clamp and a third clamp which are connected together, wherein each of the three clamps comprises a first clamping piece and a second clamping piece which are connected through a clamp axial column, an occlusion part is formed when the front ends of the first clamping piece and the second clamping piece are occluded, and a groove is formed in the middle when the occlusion part is closed; an insulating bushing is arranged at one end of the first clamping piece of the first clamp, and an external insulation connecting part and an internal conductive connecting part are connected onto the second clamping piece; the first clamping piece of the second clamp is connected with a conducting wire, and an electrical connection terminal with a conductive terminal at the top and a conductive jack at the tail part are arranged at the other end of the conducting wire; the second clamping pieces of the three clamps are the same in structure, and the third clamp and the second clamp are the same in structure; the conductive terminal of the second clamp is inserted into the connecting part of the first clamp, and the conductive terminal of the third clamp is inserted into the conductive jack of the second clamp so as to form a current path. The secondary short circuiting line for the CT and the PT can form a reliable short circuit, is simple in operation and can effectively ensure personnel safety of operating staff.