The real orbital movement of satellite has an impact on the satellite-ground quantum communication experiment. The change of satellite-ground distance leads to the change of signal time interval, and thus it affects time synchronization in quantum communication, reduces final key rate and even fails to generate keys. The satellite-ground quantum communication data can be simulated by using the fixed-point quantum communication data, which can be used to detect the time synchronization performance of satellite signals at different orbital heights before satellite launch. By analyzing the time synchronous scheme, the signal light receiving end time variation which reflects the distance change is simulated. The practical data of satellite-ground quantum communication experiment are used to verify the simulation model, and results show that the model matching degree is good.