Flatness detector

The utility model discloses a flatness detector, and relates to the technical field of flatness detection. The laser flatness measuring device comprises a mounting rack and a laser flatness measuring instrument, the laser flatness measuring instrument is mounted above the mounting rack, the inner side wall of the mounting rack is rotatably connected with a first screw rod, the peripheral side surface of the first screw rod is in threaded fit with a sliding plate, the upper surface of the sliding plate is provided with two groups of sliding grooves, and the inner side walls of the sliding grooves are rotatably connected with second screw rods; the peripheral side face of the second lead screw is in threaded fit with a sliding base, and a supporting plate is installed on the upper surface of the sliding base. Through the arrangement of the first screw rod, the sliding plate, the sliding groove, the second screw rod and the supporting plate, a to-be-detected part can be automatically translated at the bottom of