X-ray devices have been demonstrated to have the ability of revealing characteristics of material at the molecular and atomic level.This ability is particular important for detecting illicit materials.It has been proved to be an effective security inspection method and has been widely applied in public traffic stations.Aimed at a polychromatic spectrum X-ray CT system

a novel recognition algorithm of material density based on dual-energy curve is put forward

the material dual energy curve is calibrated through the gray value from high and low energy of the image.Reverse search method is used to determine the thickness of the material.The filtered back-projection reconstruction algorithm is used to reconstruct the electron density distribution of the material from

which the density information of the detected material can be obtained fastly and high efficiently.Combined with skyscan1076 CT test platform

this algorithm is verified to be correct

and the experimental results error are relative low.