The efficiency of traditional industrial CT image conversion to 3D printing G-code is low. To address this issue, a fast conversion method of industrial CT image to G-code based on the adjacent layer data matching is proposed. Firstly, the Canny operator is used to extract the contour edge of industrial CT image. Secondly, the contour bifurcation problem is processed to realize the geometric information data matching between adjacent layers. Thirdly, the contour interpolation between adjacent layers is carried out to meet the requirements of 3D printing layer thickness, so as to avoid the “ladder effect”. Finally, the G code for 3D printing is achieved by the filling coding. By using the proposed method, it takes 10. 5 s to convert the wheel CT image into G code, which is much less than other indirect conversion methods. There is no “ladder effect” in the 3D printed wheel hub, and the average dimension error rate is 0. 25% . Experimental results show that the conversion method does not involve intermediate format, and has high conversion efficiency. The conversion error is equivalent to the traditional method, which is suitable for parts with complex cavity structure.