The All Sky Imager can achieve continuous automatic monitoring of cloud cover throughout the day, with high spatiotemporal resolution and more accurate cloud cover calculation results. It mainly consists of three parts: imaging part, solar tracking device, and environmental protection system. The imaging part is a digital imaging system with a fish eye lens, which captures visible light red, green, and blue images of the entire sky at a fixed time with a sampling frequency of 3 seconds. The solar tracking device is specifically designed to calculate and track the position of the sun, block the incident light directly from the sun, and avoid strong direct sunlight from damaging the photosensitive elements of the imaging part. The environmental protection system is a temperature control system and rain and snow protection device designed according to different outdoor environments.