Currently the calibration of solar blind ultraviolet radiation detector is generally characterized by the gray scale response of it's image [1] [2]. This method can only be used when detector is exposed to a strong radiation field (> 10−9W / cm2), unable to determine the characteristics of the detector under the weak irradiance field. Using the method in this article, radiometric calibration for SBUV-ICCD can be achieved under an extremely weak (10−14W / cm2) solar blind ultraviolet irradiance field; Under the fixed integration time, the relationship between SBUV-ICCD detector response and the MCP gain is analyzed. Finally, we analyzed the influence of the uncertainty of the results of the calibration, the results showed that the maximum radiometric calibration uncertainty of about 7.1%, to meet the <10% of the calibration requirements.