Abstract: Due to the complex space environment, the influence of the atmosphere on the radio and microwave signals is one of the main error sources for the high-precision satellite-to-earth two-way time matching. In order to meet the requirements of the satellite-ground time comparison, the ionospheric error correction method and dispersive troposphere delays correction method in the triple-frequency system are studied, the main factors affecting the atmospheric error correction are discussed, and the atmospheric error correction and the satellite-ground time comparison results under different scenarios are simulated and analyzed. The simulation results show that when the satellite attitude error is controlled within 100 as, the phase center calibration error is controlled within 5 mm, and the orbit position error is controlled within 30 cm.The root mean square (RMS) of ionospheric and tropospheric error residual are less than 0.006 ps and 0.06 ps respectively after correction, and the accuracy of star-ground time comparison is better than ps level.