The invention provides a plane rectangular payingoff apparatus, comprising a laser emitter body and two laser receiver bodies; the laser emitter body comprises a stauroscope, a laser emitter, a sight line groove, a laser emitting shaft endpoint, a laser emitter switch, an optical plummet, a circular bubble, a tubular leveling instrument, a tripod, a tripod center connecting screw rod, a helix angle, a triangular base, a level brake fine-tuning bolt, a terminal disc and a cross division line; the laser receiver body comprises a stauroscope, a cross division line, an optical plummet, a circular bubble, a terminal disc, a tripod center connecting screw rod, a tripod, a helix angle, a triangular base, a tubular leveling instrument and a level brake fine-tuning bolt. The invention has the beneficial effects that: the invention saves the production cost of the apparatus, and improves the work efficiency; the precision and the theodolite are appropriate and have convenient operation and simple processing and eliminate the collimation error of the operators.