Abstract: This paper proves theoretically that the absolute dual quadric includes the whole intrinsic camera parameters and infinite plane. According to the pure translation relation of binocular vision, linear constraints are added to the absolute dual quadric, and only with two images, linear self calibration and three dimensional reconstruction can be made. Many experiments with both synthetic and real images show that our method can obtain satisfactory result and can be applied to practical vision measurement, and can be used as the initial values of nonlinear optimization.