The 3D computer vision is accomplished by a new vision system based on the combination of one camera and one mirror instead of binocular vision system. It is proved theoretically that if the mirror is placed in the certain conditions, the images that can be used to accomplish 3D stereo vision restoration is obtained from the combination. The point′s world-coordinates are calculated theoretically by use of the images, supposing the interior and exterior parameters of the combination are known. The calibration, parameters calculation and point′s 3D stereo restoration of the combination are also deduced theoretically. It is also proved that the essence of the combination′s 3D restoration is identical to the binocular vision system. Experiments are presented to contrast the performances of the two methods. The results show that the accuracies are nearly equal.