To compensate for the insufficient signal-to-noise ratio, which cannot be accurately localized in two-dimensional space to analyze the flicker noise characteristics of an image intensifier, this study designs a low-light image intensifier flicker noise test method based on a discrete coefficient and Harris corner point detection for the image intensifier flicker noise characteristics. In this method, a high-frame-rate image acquisition system based on a Gsense400BSI CMOS image sensor was used to realize flicker noise image acquisition that matched the afterglow time of the fluorescent screen of the image intensifier. By calculating the pixel-level discrete coefficients of the images acquired from consecutive multiframes, a hotspot map was visualized. In addition, the Harris corner detection algorithm was used to accurately analyze the flicker noise in each region of the fluorescent screen of the image intensifier and mark the bright noise spots on the fluorescent screen. The experimental results show that this method can realize the two-dimensional analysis and localization of the flicker noise of the image intensifier and thus provide technical support for the performance optimization of the image intensifier and testing of noise characteristics.