A method and system for CT image correction are provided. Contour data of a scanned subject can be obtained, and a shape image of the scanned subject can be reconstructed according to the contour data, wherein the contour data of the scanned subject can be obtained by scanning the scanned subject through a piece of visual equipment. Original CT projection data of the scanned subject can be obtained, and a CT image can be reconstructed according to the original CT projection data. For determining a supervision field image, image matching can be performed between the shape image and the CT image of the scanned subject. Supervision field projection data can be obtained, and the supervision field projection data can be used to correct the CT image.
