To assess the solar blind image intensifier, a wide spectrum and large dynamic test system for absolute spectral response of solar blind UV image intensifier was designed and realized based on the standard alternative method. The test system took an ultra-high brightness, high stability broadband laser-driven EQ99 as the basic light source, the spectral-meter as the monochromator and the NIST calibrated silicon trap detector as the reference detector. It also achieved the low current measurement by using a high-accuracy electrometer and a variety of remedies. Experimental results indicate that the system covers spectrum of 200 nm ~ 630 nm and a dynamic range up to 106, and the uncertainty is less than 5.5%. The auto-test system is stable, high-precision and meets the solar blind image intensifier assessment requirement.