Underground water level surveying equipment

The invention belongs to the field of water level surveying and relates to underground water level surveying equipment. The equipment comprises a water tank, a horizontal sealing plate which is arranged on the water tank and provided with a first through hole, a floating plate which is arranged in the water tank, a stand column which is erected on the floating plate and penetrates out of the first through hole, a supporting plate which is arranged at the upper end of the stand column and parallel to the floating plate, and a water level surveying body which is arranged on the supporting plate; four sliding grooves distributed in a cross shape are formed in the upper surface of the sealing plate, sliding blocks are embedded in the four sliding grooves in a sliding mode, the positions of the sliding blocks correspond to the positions of the corners of the supporting plate in a one-to-one mode, and first connecting rods are hinged between the sliding blocks and the corresponding corners of the supporting plate t