Abstract: In order to achieve precise pin-point landing in deep space exploration missions，a new approach is presented to estimate accurately the lander’s attitude and position based on line correspondences during descent phase. Firstly，lines on the images taken by onboard navigation camera are detected and matched in this algorithm. The linear equations are deduced by n lines and their projection lines. Then，according to the Singular Value Decomposition，the candidate solutions are computed. Lastly，the unique solution about the attitude and position of the lander is obtained by using the least square method. The extensive experiments demonstrate that the error of attitude is less than 0.1° and the error of position is less than 2 m.