For the demands of surgical navigation, this paper proposes some simple 3-D point reconstruction methods. These methods regard the perpendicular feet on back-projection lines as the measurements of a 3-D point, since these feet are close to the 3-D point. And then the methods utilize the distance between 3-D point and camera and error propagation rules to adjust the weights of the feet. Finally, the weighted average of these feet is taken as the final estimation for the 3-D point. They are easy to implement, and can be used in both biocular systems and multiocular systems. Especially, as these methods have closed-form solutions, their errors can be predicted by using error propagation rules. Experiments show that they are faster and more accurate than iterative methods and their error covariance matrix can be exactly predicted.