Abstract: In the research of relative pose for spacecrafts based-on machine vision,the feature extraction algorithm was the basis of relative pose.A feature extraction algorithm for spacecrafts based-on mathematical morphology was proposed.Infused organically the attitude and orbit(information) of spacecrafts,structuring elements were reconstructed dynamically in feature(extraction) of this algorithm.The simulations show that this algorithm is a valid method to solve the problems of spacecrafts feature extraction.It is also especially valuable for the thought of structuring elements selecting dynamically to use in correlative research fields