Abstract: In the application of industrial CT imaging, The X-ray energy mismatch to the effective thickness and traditional scanning is difficult to preserve the data integrity of projection due to the limit of complex-structure's shape, structure and so on. Therefore, changing the general scanning trajectory to make up for the deficiency of projection data, and then deriving the iterative reconstruction algorittun along a general scanning trajectory. First of all, in the base of general scanning trajectory, we combine the knowledge of analytic geometry with the projection to obtain the projection matrix. The second, the iterative reconstruction algorithm is no binding trajectory, so we study the iterative reconstruction algorithm along a general scanning trajectory. Finally, according to the numerical simulation of small cone-beam angle, lager cone-beam angle scanning and different thickness of structure testing to verify the correctness and feasibility of the algorithm. For the different thickness of structure, compared to the traditional circle scanning, this method is better for preserving the data integrity of projection and improving the quality of reconstructed image.