The difficulties of large-range long-distance detection are discussed. A dual field of view large aperture lens based on rotary scanning is designed to increase the detection range and distance of the system. The grouping design is used, the aperture of the front group system is compressed, and the galvanometer swing is used to compensate the image shift phenomenon during the rotation. So that the generated images can be stabilized and the detection accuracy is improved. The ideal system transfer function and dispersed spot are obtained through simulation, and large-range detection can be realized using rotary scanning of the large aperture system. This design provides a new way and idea to improve the insufficient of the detection distance or the range of the staring system.