Abstract: To integrate industrial computed tomography (CT) technology with rapid prototyping (RP) directly, a new method creating an RP slice file directly from industrial CT slicing images is presented. Firstly, through edge extraction and contour de-noising, connecting, thinning and tracing, the basic contour point data of the interior and exterior structure of a sample piece are obtained. Subsequently, matching point pairs between adjacent layers are established, interlayer contours are got by linear interpolation, and then all contours are fitted by cubic B-spline curves. Finally, a CLI file is created after contour point sampling and interior and exterior contour recognizing. The CLI file is then input into an RP system and a product is manufactured. Applications of the method prove that it is