Expansion monitoring device, system and method based on laser positioning mode

The invention provides an expansion monitoring device, system and method based on a laser positioning mode, and belongs to the technical field of thermal engineering, the device comprises at least one expansion indicating unit, the expansion indicating unit comprises a fixed rod, a laser, a displacement dial, a data acquisition communication module and a first frame body, and when the displacement dial is a photosensitive displacement dial, the data acquisition communication module is connected with the fixed rod; the expansion indicating unit further comprises a first collecting module, and when the displacement dial is a non-photosensitive displacement dial, the expansion indicating unit further comprises an image collecting module. The expansion amount of the thermal equipment is transmitted to the laser through the fixing rod, a light beam of the laser irradiates the displacement dial corresponding to the laser, the first acquisition module acquires light beam offset data or the image acquisition module a