A halo tester is designed to analyze the halo formation in low-light-level (LLL) image intensifiers and the influencing factors on halo size. The tester is used to collect a 0.1922-mm hole image directly using a CoolSNAPK4 charge-coupled device (CCD) in a darkroom under illumination conditions between 10 2 and 10 4 lx. The practical measurement result shows that the amplification ratio is 343.4. Then, the super second- and third-generation image intensifiers are placed after the hole, and the halo sizes of the hole images on the screens are determined as 0.2388 and 0.5533 mm, respectively.