IR zoom lenses are mostly used in relatively wide outdoor scenes with the aim to increase focal length for getting long-range detection. Since the focal length can be changed during operation, the key part of the scene can be zoomed in and observed, thus providing a better monitoring system. With the continuous development and improvement of the security industry and outdoor infrastructure, zoom lenses are being utilized in many industries and fields such as highways, railways and bridges, coastal and border defence, and many other scenarios.