Abstract: An image-rotation system which could efficiently enhance its scanning performance at a large scanning range was designed to eliminate the effect of the image rotation in a cancellation form according to the characteristics of the reflector prism that might adjust the optical axis and generate the image rotation, since the panoramic system composed of an imaging system and controllable scanning mirror usually produces the image-rotation phenomenon. The influence of prism fabrication and other factors on the clear aperture was eliminated by the arrangement of the flat reflectors instead of the reflective prism. The reason that the scanning mirror generates the image rotation was analyzed according to the image-rotation theory. The feasibility that the mirror combination can solve the problem of the image rotation was illustrated with examples.