The invention discloses a method for vetorizing a raster image. The method comprises the following steps of: shooting the image of a material object by using a digital camera and saving the image in a bmp format; eliminating the background of the image through manual interaction by using a graph cuts segmentation algorithm, and saving the acquired image in the bmp format; and vectorizing the image which is output in the last step by using an improved octree color vectorization-based vectorizing algorithm and the manual interaction, and saving an output file in an svg format. The format of theoutput file is based on scalable vector graphics (SVG), so that a vector graph designed by the method has transportability; and the octree color vectorization-based vectorizing algorithm is improved in the vectorizing process and the manual interaction is applied, so that the vector graph designed by the method has a better effect than that designed by other vectorizing software.