The invention provides a device and a method for automatically matching laser radar receiving and transmitting optical axes. The device comprises an emergent light path, a receiving light path and a data acquisition and control portion, an emergent system comprises a laser, a beam expanding system, a plurality of reflecting mirrors and lenses, laser light is emitted to air through the beam expanding system, the lenses, the reflecting mirrors and an optical antenna, a receiving system comprises a telescope, echo signals sequentially pass an optical fiber, the lenses, a light filter and a photoelectric detection element, the photoelectric detection element is arranged at an input end of a data acquisition system, and an output end of a control system controls the optical antenna with a high-accuracy servo motor through a motor driving controller. The method automatically traces the echo signals by the aid of a program design two-dimensional spiral scanning algorithm, uniaxial scanning and matrix scanning are performed to obtain the best emitting antenna position, so that an emitting antenna points to and receives collimation of the optical axis of the telescope, operators no longer need rich experience, and the method is simple and convenient to operate and high in feasibility.