Abstract: We proposed a refinement method of solar radiation perturbation model in autonomous orbit determination of navigation satellites.With this method,the prediction errors of GPS satellites’ Ω and i could be controlled at ±40 mas level during 180 days.As a result,the tangential and normal direction precision of satellites’ orbit improved in the autonomous orbit determination when constrained the predictions of Ω and i.Finally,user range error became smaller.However,this method has small influences on radial direction of orbit as well as clock bias.