In this paper, we put forward an improved non-photorealistic rendering method for generating a colored pencil drawing from digital image. First, to make sure the result can retain the original color information, we use the original pixel value instead of the black dot which generated by the traditional white-noise generating method. Second, we added a ratio for the Kirsch operator to be suitable for different images with different details. Third, we present a new approach which extruded form the luminance of the original image to determine the stroke orientation. Based on our methods, the quality of traditional pencil illustration can be guaranteed to a certain extent, and an effective and convenient tool is provided to generate the same drawings in style with artists and illustrations even for the users that have not been trained professionally.