Flatness calibration device for surveying and mapping engineering

The invention relates to the field of surveying and mapping engineering, in particular to a flatness calibration device for surveying and mapping engineering, which comprises a U-shaped plate, a laser pen and more than one blocking rod, the blocking rods are vertically arranged in the U-shaped plate, one end of each blocking rod is provided with a fixing frame, a first roller is arranged in each fixing frame, and the middle of each blocking rod is provided with a through hole. The other end of each blocking rod is provided with an extrusion mechanism, the top face and the bottom face of the U-shaped plate are each provided with a glass plate, a mounting pipe is arranged above the glass plate at the upper end, the laser pen is inserted into the mounting pipe, and the top face and the bottom face of the U-shaped plate are further each provided with a second roller. The device is simple in structure, mounting and dismounting of the laser pen are facilitated, once a wall surface is uneven, the first roller and th