A laser level uses a laser beam to replace a level of manual reading. The laser beam emitted from the laser is introduced into the telescope cylinder to emit a horizontal laser beam in the direction of the collimation axis.

Using the monochromaticity and coherence of the laser, a piece of glass or metal sheet with a certain light-shielding pattern, that is, a zone plate, can be assembled in front of the telescope objective lens to cause diffraction interference. After focusing by the telescope, a bright and fine cross-shaped or circular laser spot is obtained within the focusing range of the zone plate to more accurately align the target. Leveling can be performed by providing an optically-receiving target that can be automatically tracked on the front and rear level gauges. In construction surveys and large component assembly, laser level is commonly used to establish horizontal or horizontal lines.

The digital level is currently a good level. With a special bar code level gauge, the digital reading system built into the instrument automatically acquires the bar code reading of the leveling ruler, eliminating the need for manual reading. This kind of instrument can greatly reduce the labor intensity of surveying and mapping work, avoid artificial subjective reading error, and improve measurement accuracy and efficiency.