The utility model discloses a limit switch. The limit switch comprises an outer cover, an inner cover, an upper housing, a lower housing and a rotating shaft. The bottom of the inner cover is provided with a gasket, the outer cover is mounted to the upper housing, the upper housing is provided with a through hole, a bearing is arranged at the position, corresponding to the through hole, of the lower housing, and the lower housing is provided with a first cam, a gear, a fixing pillar, a second cam, a microswitch and a bonding cap. A mounting hole is disposed, corresponding to the bearing, in a support, the upper end of the rotating shaft is pivoted to the inner cover, the rotating shaft sequentially penetrates the gasket, a spring, the bearing and the mounting hole. Two ends of the spring are respectively pressed against the gasket and the bearing, the spring sequentially penetrates the first cam, the gear, the fixing pillar and the second cam. The inner wall of the first cam is engaged with the gear, the gear is connected with the second cam through the fixing pillar, and both the first cam and the second cam contact the microswitch in linetype. According to the limit switch, the positional accuracy of the first and second cams and the microswitch is improved, and the limit switch can be more conveniently used.