Abstract: Since the X-ray beam has the characteristics of wide spectrum in the cone beam X-ray computed tomography imaging system, this leads to the X-ray hardening effect, so as to make the reconstruction image in the goblet artifact and strip artifact.It is necessary to study methods of the hardening correction in order to reduce the effects of hardening effect.A method of beam hardening correction is put forward, which is based on the experimental spectrum and Monte Carlo simulation of polynomial fitting.Based on the initial X-ray energy spectrum by experimental measurement, the relationship between transmission thickness and pluripotent projection can be obtained by exploiting Monte Carlo simulation. And then using polynomial fitting can obtain relationship between pluripotent projection and equivalent single projection, so as to realize hardening correction. This method and the traditional filter method for X-ray hardening correction on the aluminum workpiece were respectively used. The experimental results show that the proposed method is better than the filter method which can decrease cone-beam CT beam hardening artifacts effectively.It provides an effective correction method for cone beam industrial computed tomography beam hardening correction.