The invention discloses a switch electrode and a switch using the switch electrode and applied to an electrical power system. The switch electrode comprises a body of a tubular structure, wherein the cross section of the body is of an annular structure, an inner ring of the annular structure is round, an outer ring of the annular structure comprises four sections of connecting arcs which are evenly arranged in the circumferential direction and have the same first curvature radius, and every two adjacent connecting arcs are smoothly connected through a transition arc which has a second curvature radius. The switch electrode is of a special structure. Compared with an existing switch electrode, the switch electrode has the advantages that distribution of electric fields on the surface of the electrode with the special structure is evener, the phase interval and the width of a cabinet can be effectively reduced under the condition of the same insulation level, the structure of the cabinet can be more compact, cost is reduced, and the occupied area is reduced; in addition, compared with an electrode with a round outer ring, the switch electrode of the special structure can be installed and positioned more easily.