Abstract: A multi-satellite tracking telemetry and command(TT&C) scheduling model was proposed, guiding by the engineering requirement, and genetic algorithm was used to solve the problem，which aimed at solving the multisatellite conflict problem. Based on the global and local searching strategies, taking usable time windows as object, all usable time section encoding(AUTSE) and cooperative coevolution GA encoding(CCGAE) were designed, the processes and operators of the algorithms were described, then the efficiencies of the two encodings were analyzed. The solution quality and time spending performances of the two encodings were examined through simulation, and the applicable scope of the two encodings and corresponding searching strategies was summarized. The system adopting above results has been applied to the auxiliary decision-making of spaceflight top-level design successfully.