Abstract: The image transfer signal-to-noise ratio isan important parameter which can characterize the combination property of image intensifier all-roundly and quantitatively when detecting the weakly radiative image.It has the important significance for determining the detection sensitivity threshold of image intensifier.Based on its test principle,a highly sensitive and low noise CCD is adopted as the output image detector and the digital image processing technology is introduced.The automatic test of image transfer signal-to-noise-ratio of typical target is realized by using a test system we designed.The experimental results getting with several test show that the test process is automatic and fast and the tested data is accurate and steady.The uncertainty is below +-3% in the same test condition.