Abstract: In order to optimize the performance of GEO and LEO laser communication system, the simulation model of satellite communication orbit characteristic was established. The simulation model was designed. Through analysis of satellite data within one year, the range of Doppler frequency shift of satellite communication terminal is 5109 Hz, Doppler frequency shift compensation method can be used to reduce the influence of Doppler frequency shift between GEO and LEO. For coherent communication, frequency shift must be compensated by terminal. The range of point-ahead was larger than laser beam divergence angle, so the lead angle should be compensated by terminal, in order to reduce the influence of relative velocity on laser communication; the laser communication system need amend early according to point-ahead of LOS, the sun interference and earth occlusion have a longer time, satellite network should be carried out to improve the available probability, in the communication process the work flow of the two communication terminals was optimized based on the communication terminal time; LOS changing situation of GEO and LEO terminal was different, so different structures of the satellite should be designed.