The invention relates to an apparatus and method for the geometric factor self-calibration of a laser radar and belongs to the laser atmospheric remote sensing technical field. The device comprises a laser, a main wave pulse generator, a secondary receiving mirror cover, a secondary receiving mirror, a light guide optical fiber, a main receiving mirror cover, a main receiving mirror, a reflex mirror, a red and green dichroic light splitter, a 1064nm narrowband filter, a APD detector, a blue and green dichroic light splitter, a polarization and beam splitting prism, a first 532nm narrowband filter, a first PMT detector, a 355nm narrowband filter, a second 532nm narrowband filter, a second PMT detector, a third PMT detector and an integrated acquisition system. The apparatus and method of the present invention have great advantages in terms of system scale, cost, usability, reliability and the like.