Abstract: In order to achieve real-time selection of navigation satellites in multi-constellations navigation system, a novel satellite selection method named Genetic Satellite Selection Method (GSSM) is proposed. Combined with the basic idea of genetic algorithm and the feature of multi-constellations navigation system, a fast crossover operator and mutation operation is described. The experiment results show that, in the satellites selection process, the GSSM can effectively reduce 98.9% computation comparing to the traditional optimal Geometric Dilution of Precision (GDOP) method. From the view of the overall navigation system, it can also reduce almost 73% computation.