The present invention relates to the technical field of automobile maintenance and device calibration, and discloses a calibration device of an automobile assistance system, the radar calibration device including a support assembly, a beam assembly, and a sliding member. The beam assembly is mounted to the support assembly and may move relative to the support assembly along a vertical direction. The sliding member is mounted to the beam assembly and may move relative to the beam assembly along a horizontal direction. The calibration device of the automobile assistance system may cause a simulator to be mounted on the sliding member that may slide horizontally from left to right, so that the simulator can slide continuously from left to right, radar for blind areas at a left rear and a right rear of the automobile are conveniently and rapidly calibrated, and consistency of parameters such as a height and an angle of the calibration device of an automobile assistance system can be ensured, achieving a convenient and more accurate calibration operation.