The invention relates to the photoelectric technology field, in particular to a laser water level gauge based on laser distance measurement. The laser water level gauge comprises a laser distance measuring instrument, an adjustable beam contracting system, a high-precision light sensing CCD, an upper tray, a lower tray, a cross-shaped level gauge, a screw, a data processing system and a supporting frame. The laser distance measuring instrument is fixedly arranged on the lower tray. The adjustable beam contracting system is located at a laser emitting opening front end of the laser distance measuring instrument. The high-precision light sensing CCD is fixed on the right side of the laser distance measuring instrument and the output end of the high-precision light sensing CCD is connected with the data processing system. The cross-shaped level gauge is fixed on the surface of the upper tray. One end of the supporting frame is fixed on the lower surface of the lower tray. The upper tray and the lower tray are connected through the screw. By means of the laser water level gauge based on laser distance measurement, the vertical precision of an incoming laser beam and a measured liquid level is high and meanwhile, the measurement errors are reduced and the height of the measuring liquid level can be efficiently and accurately measured. The laser water level gauge based on the laser distance measurement has the advantages of being simple in structure, reasonable in arrangement, low in manufacturing cost and the like.