In order to achieve ocean optics ultraviolet remote sensing, it is needed to make an accurate radiometric calibration and system performance measurement for the UV imaging detection system. The method of integrating sphere spectral radiometric calibration, with xenon lamp as the light source, is used to calibrate the ultraviolet imaging detection system, which is designed and developed by ourselves. It’s verified that the output response of the UV detection system to the output spectral radiance from integrating sphere is an excellent linear relationship under the same integration time by taking the average of multiple samples, whose linear correlation reaches 99.99%. We have found the xenon lamp with a property of fluctuation, whose output spectral radiometric has ups and downs. In this paper, we firstly propose a model for xenon lamp, which is based on the relationship of three kinds of standard deviations of experimental results, UV imaging system and xenon lamp. This model can be used to correct the 48% inaccuracy of negative effect by the fluctuation of xenon lamp, and finally fix and get the real noise and SNR of whole system. Through the theoretical analysis, the establishment and verification of fixed model, it could provide theoretical and data support for xenon lamp integrating sphere UV calibration and parameters measurement like SNR.