利用蒙特卡罗方法模拟了锥束工业CT系统中X射线的产生过程，分别得到了未加过滤层和加2 mm铁片作为过滤层情况下的X射线能谱；计算了不同靶面倾角下出射X射线相对强度的角分布。随后模拟了X射线通过被测物体后射线强度的分布，分别得到了射线源与探测器间距离相同时，穿过不同直径被测物体以及经过相同的被测物体，但射线源与探测器间距离不同的两种情况下的系统SPR值的分布以及探测器平面不同位置下射线强度的分布。此外还模拟得到了有无被测物体情况下的探测器中心位置的通量能谱分布及一些特殊位置下射线强度的空间分布。模拟结果可以为CT系统图像重建时的散射校正和射束硬化校正提供数据依据，有助于确定探测器单元的最小灵敏度以及为系统的屏蔽防护设计提供参考。

In this paper, the physical process of producing X-rays in the X-ray source used in cone-beam industrial CT system was simulated by Monte Carlo method. The X-ray spectrums with and with no 2 mm iron as filter layers were obtained, respectively. In addition, the angular distribution of the outgoing X-ray flux under different target angles was calculated. Then, the intensity distribution of the X-rays which passed through the object under test was simulated. We obtain the distribution of SPR value and the distribution of X-ray intensity in different positions of the detector plane in different conditions, which are in the same distance between the ray source and the detector and passing through the object of the same diameter. Besides, we also obtain the flux spectrum distribution in the centre of detector and the spatial distribution of the X-ray intensity in some special position. The simulation results in this paper can provide some help and basis for the scatter correction and beam hardening correction in the process of image reconstruction and help to determine the minimum sensitivity of the detector, and provide a reference for the shielding system design.