The manufacturing technology of cylindrical mirror used in conic approximate Wolter-I X-ray focusing telescope is hot slumping glass segments, which makes the thin glass substrate replicated on the convex surface of cylindrical mandrel. The most important errors of cylindrical glass are the figure error and ripple error, which are the major factors affecting the focusing performance of telescope. Therefore, the high-precision and quickly measuring low and mid spatial frequency error of concave surface and convex surface of cylindrical glass is the key technology in manufacturing process. The traditional test plate can′t meet the requirements because it can only measure specific surface with the same of radius of the test plate inefficiently and can′t measure the thin glass. The convex surface of smooth cylindrical mandrel and concave surface of thin cylindrical glass were measured by an interferometer with both computer generated hologram (CGH) and laser scanner quickly and quantitatively. Also, with the two testing methods, the power spectral density(PSD) of cylindrical glass was calculated and the point spread function (PSF)and half power diameter (HPD) were plotted by fitting slope error. It demonstrates that the two methods can characterize the influence of the low and mid spatial frequency error on the angular resolution of X-ray telescope, which benefit for improving the precision of the manufacturing mirror and the focusing performance of X-ray telescope.