Self-centering laser angle measuring system

The invention relates to a self-centering laser angle measuring system, belongs to the technical field of optics, and aims to solve the problem that an angle measuring photoelectric sensor exists in an existing scheme, but light beam angle drifting exists in the existing scheme. The prism group is composed of two beam splitter prisms: a standard beam splitter prism (15); and a beam splitter prism(14) plated with a reflective film (13). When the laser beam generates an angle drift amount theta (12), the generated laser beam (2) is divided into two beams through a light splitting surface (17) of the beam splitting prism (15), one beam is transmitted normally, and the other beam is transmitted to a light splitting surface (16) of the prism (14), reflected downwards and then reflected by thereflective film (13). According to the invention, measurement errors caused by laser beam angle drift to target measurement can be effectively suppressed only by adding the beam splitter prism group without adding an additiona