A panoramic optical annular staring imaging sensor for atmospheric limb detection was presented, which could be used to image the surrounding 360°scene at one time without rotating the optical system and satisfy the application requirement. For the particularity of the wavelength band in Ultraviolet (UV), the signals accepted by the instrument are very weak. Signal-to-noise Ratio (SNR) is one of the key parameters to quantitatively evaluate the image quality, so the modeling analysis and measurement of SNR are important for developing UV panoramic limb imaging sensor. First, analyze the SNR model of the panoramic limb imaging sensor. And then deduce the SNR mathematical expressions. Finally, the SNR of the panoramic limb imaging sensor is theoretically evaluated and the coherent experiment is built to prove the result. The experimental results match the theoretical value well, which indicates that SNR modeling analysis method is feasible for UV panoramic limb imaging sensor.