A CT system and method thereof are disclosed. The system includes: a conveyor mechanism; a first scanning stage configured to scan the object and generate a first digital signal; a second scanning stage spaced from the first scanning stage at a preset distance in a direction of the object's movement; a processing device configured to reconstruct a CT image of the object at a first image quality based on the first digital signal, and analyze the CT image; and a control device configured to adjust a scanning parameter of the second scanning stage based on an analysis result of the processing device to cause the second scanning stage to output a second digital signal. The processing device reconstructs a CT image of the object at a second image quality higher than the first image quality at least based on the second digital signal. The system takes full advantage of the distributed ray sources which replace the normal slip ring technology.