The invention relates to a calibration system used for verifying assembly line time value. The calibration system comprises a standard test room and tested laboratory satellite receiver, a standard test room and tested laboratory cesium atomic clock, a standard test room and tested laboratory micro jump meter, a standard test room and tested laboratory precise counter and a standard test room and tested laboratory data processing system. The satellite receiver receives a locked satellite signal and generates a 1pps second pulse signal. The cesium atomic clock locally generates a high-precision and stable 1pps second pulse signal. The second pulse signal generated by the satellite receiver and the second pulse signal generated by the cesium atomic clock simultaneously access the precise counter for comparing. The data processing system is used to acquire the time difference between a standard clock and a satellite clock and the time difference between a tested clock and the satellite clock. The standard clock and the tested clock are adjusted. According to the technical scheme of the invention, remote calibration timing can be carried out on a remote clock, and at the same time a calibration result can be traced to national time frequency reference.