A CT system and method thereof are discloses. The system includes: a fixed multi-plane multi-source X-ray generation device and a control system thereof that provide X-ray source used in luggage inspection; a single-energy, pseudo-dual-energy or spectral detector system and data transfer system that receive perspective data of X ray penetrating the luggage, and transfer the data to a computer for processing; a conveyor and a control system thereof that control a speed for moving the luggage forth and back, and perform tomogram scanning; and a host computer system that performs tomogram reconstruction and provides man-machine interaction. The system takes full advantage of characteristics, such as high speed and stability, brought by the distributed ray sources which replace the normal slip ring technology. The system also adopts the idea of inverse-geometry CT, and reduces detector area and cost by increasing the number of ray sources. With the reduction of detector area, cone-beam artifacts and cup-shape artifacts caused by scattering are also reduced, and influence of the oblique effect on registration of dual-energy data is suppressed.