Abstract: Camera calibration is an important part of computer vision. The theory is based on the formation of orthogonal vanishing point under perspective projection and linear calibration for a camera. A novel camera self-calibration method based on orthogonal vanishing point is presented, of which the target is the regular prismoid where a top is the regular polygon that can contain a set of points at infinity in orthogonal directions and sides are congruent isosceles trapezoids that also contain a set of points in infinity in orthogonal directions. The point at infinity is called the vanishing point in the image plane. According to the constraints of the orthogonal vanishing points to absolute conic, the intrinsic parameters of a camera can be solved linearly. The experimental results show that the algorithm can accurately and reliably estimate the intrinsic parameters of the camera and it is very close to the actual situation.