The application provides a voltage and current combined sensor and a voltage and current detection system. The voltage and current combined sensor comprises a fixed support, a movable support, a first lead fixing mechanism, a second lead fixing mechanism, a locking handle, a linkage mechanism, an electric field sensor probe and a magnetic field sensor probe. The electric field sensor probe comprises a PCB substrate, a first electrode group, a second electrode group, a first binding post and a second binding post; the first electrode group comprises a plurality of semiorbicular first electrodes successively in series connection, and the second electrode group comprises a plurality of semiorbicular first electrodes successively in series connection; the magnetic field sensor probe comprises a first iron core, a second iron core, a Rogowski coil, a third binding post and a fourth binding post. The voltage and current combined sensor reduces insulation design costs, does not need to be in direct electrical connection with a power transmission line to be detected, and improves safety.