Abstract: A scheme of range and attitude measuring for soft landing on the asteroids based ona terrain feature database was presented.First,the terrain feature database about a landing target was established which contained the longitude and latitude data of the feature points,image texture information and position-correlation of the feature points.Then,after terrain feature extraction was performed during the descent,image matching was processed in the database.The spill problem of feature points out of a camera was solved,and the applicability of the optical measurement was improved.Finally,the relative positions and attitudes between the asteroid and the explorer were obtained by computer vision principle associated with the position of the matching points.The feasibility of this scheme was validated by mathematical simulation.