Global navigation constellation maintenance is an important problem. Firstly, the model of MEO constellation formation was advanced. Then, with consideration of main perturbation forces and orbit ephemeris error, the constellation formation evolvement law was analyzed and asserted with some satellites orbital data. Also, anti-perturbation compensation strategy was put forward, an improved decoupling control method was proposed, and the effect of satellite launch time on anti-perturbation compensation strategy was discussed and analyzed. Finally, some key results were concluded as a summary, which will be helpful for the design of the global navigation constellation with inertial space and its maintenance and control strategies for its rotation around the earth.