Our home-made nonlinear auto-adjusting iterative reconstruction technique(NAIRT) was used to reconstruct a field rich in high-frequency components.A piece of cylindrical PVC pipe was selected to simulate axisymmetric fields.Its normal cross sections are PVC rings.As far as reconstructed fields are concerned,PVC rings are their rectangular pulse signals.The PVC pipe was normally transmitted by X-rays,and the transmitting image,called projection,was recorded.The PVC pipe was sliced by normal direction.The relative projection data of each slice could be extracted out from the projection image easily.One slice′s projection data were directly inverse-projected for iterating reconstruction.The iterating algorithm used here is our home-made NAIRT.As results,the absorption coefficient of PVC to X-ray is about 2.2~2.6.The thickness of each PVC ring is 10 pixels,and its external diameter is 96 pixels.Based on PVC pipe parameters,the error of the reconstructed PVC ring′s thickness is about 0.46 % relative to the pipe external diameter.The reconstruction data were transformed into grayscale image.As results,no matter how to quantize grayscales,the thickness of the PVC ring kept uniform and constant.The edges of rings show clear and distinct.This means that the reconstructed PVC rings are very steep in signal data.As far as signal analysis is concerned,the rectangular pulse signals of PVC rings were accurately reconstructed.Based on analysis above,we considered that,NAIRT could be competent to reconstructing a field rich in high-frequency components.