The present invention relates to the technical field of automobile maintenance and device calibration, discloses an on-board radar calibration device, the on-board radar calibration device including a laser-corner reflecting apparatus. The laser-corner reflecting apparatus includes a laser and a corner reflector, the corner reflector being mounted to the laser. The laser is configured to emit a laser, so as to calibrate positions of the corner reflector and an on-board radar. The corner reflector is configured to reflect a radar wave emitted by the on-board radar, so that the radar wave returns along an original path, to calibrate an installation angle of the on-board radar. In the present invention, the corner reflector and the on-board radar may be calibrated using the laser, and then the on-board may be calibrated using the corner reflector, without the help of other calibration apparatuses, simplifying operations for calibrating the on-board radar.