Abstract: The photon-counting imaging technique, which can detect and intensify the faint signal under the low-light-level condition, has beeb widely used in the military, astronomy, physics, chemical, biology etc.fields with the development of LLL image intensification technology and weaklight imaging elements. Introduced The working principle , characteristic and application of the photon-counting imaging are introduced. The effect of the niose on the photon-counting imaging quality is discussed.