The Extreme Ultraviolet Telescope(EUT),as a high-resolution imaging instrument,its optical performance measurement directly impacts on the image quality,so the imaging performance of aligned EUT is tested in this paper.The measuring method is to place a resolution test-target on the focal point of a collimator and the target is illuminated by a avisible light.Then,the visible light is becomed a parallel light to go through the EUT and image at focal plane on the CCD.By analysis the image,the resolution of the telescope can be obtained.The test results indicate that the angular resolution of the EUT is 1.22″(λ=570 nm),which is very close to the resolution limit(1.20″).After the computation,it concludes that the operation wavelength resolution is 0.32″,which can meet the requirement for design.