In order to meet the demand for distributed joint timekeeping system, a remote time comparison system was designed, which includes satellite co-visibility, satellite bi-directional, and fiber bi-directional time comparison means. The domestic equipment used in the system has the same time comparison accuracy as imported equipment, achieving high-precision clock difference measurement between laboratories using multiple means. The relative zero value calibration of the time comparison equipment was completed using a mobile calibration station, and a 20-day time comparison was conducted between laboratories that were 50 km apart. The experimental results show that the mean clock difference measured by the three comparison means at the two locations is less than 1 ns, the trend is the same, and the amplitude is similar, and all can accurately measure the clock difference between the two locations.