A solid-state composite switching device comprises a mechanical switch QF, a thyristor valve group, an arc suppression transformer and an arc suppression power supply; The mechanical switch QF is connected in series with the high-voltage side of the arc suppression transformer and then connected in parallel with the thyristor valve group; A low-voltage side of that arc suppression transform is connected in parallel with the arc suppression pow supply; The thyristor valve group is connected with the valve-based electronic equipment; The thyristor valve group, the mechanical switch QF and the arc suppression power supply operate according to the opening and closing commands issued by the valve-based electronic equipment respectively; The composite switching device provided by the invention is suitable for medium-voltage distribution power system, has no arc and overvoltage under any working state, and has small energy loss, meets the needs of frequent operation of switches in medium-voltage distribution power system, and prolongs the service life of mechanical switches, which has very important significance in industrial production.