In the course of determining the aircraft model attitude in the spin time based on the stereo vision,the occlusion causes much trouble.A new way based on the credit coefficients is shown and it is mainly applicable to the problems with feature matching.In the occlusion problems,it is always the hardest to get the best optimal estimation of the occluded parts.The credit coefficients can weaken the effect of the features with poor definition.So the course for searching the occluded features is mainly based on the reliable features.Simulations and experiments on real images validate the reliability of our method and the results are good enough for the aircraft spin experiment.