In order to realize the irradiance calibration of SBUV-ICCD (solar blind ultraviolent Intensified change-coupled device) with dynamic range reaching 120 dB, a light source with long dynamic range was designed and realized. Firstly, the irradiance dynamic range was estimated. Then using deuterium lamp, integrating sphere, precise stop and rail, an ultraviolent light source was developed, which has fixed structure of spectrum, but the irradiance can change continuously in long range. At last the light source’s performance was tested. The result shows that the irradiance between 0.278 and 2.8×10-7 μW·cm-2 was covered, and the stability was 0.93%/3 h. So the demand of calibration of irradiance was satisfied. It will help for measuring the surface uniformity of detector and the calibration of imaging systems.