Mid-wave infrared imaging has the advantages of all day, high resolution, strong adaptability to the environment, so it is widely used. In high-speed target tracking and aiming. The target flying speed is extremely fast and the DOF (depth of field) of the fixed focal lens is limited, so the zoom lens is required. In order to ensure that the tracking target will not be lost, a fast zoom requirement of no more than 0.3s is proposed. According to the requirements, a compact athermalized mid-wave infrared dual field fast zoom lens is designed. The focal length is 400 mm and 200 mm, and the passive athermalization design is adopted which can meet the working temperature of-40° to + 60°. the lens can match the cooling detector with effective pixel of 640 × 512, size of 15 μm and F/4.The volume of the detector can be controlled in the range of L (196mm) × w (116mm) × H (185mm). The zoom group structure is considered in the design, and the switching time is less than 0.12s, and the image plane is stable when the zoom group switching. © COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only.