Abstract: An engineering drawing vectorization method based on the feature segments is proposed in the paper.By abstracting the run length segments with the marked feature as well as setting up feature vector line segment, and extending,combining and getting intersection for the line segments,the exact vector lines can be obtained.To avoid the oddity of the burr as well as small bend lines in the vectorization,an orthogonal bipolar vectorization algorithm is used in the X direction and Y direction respectively for the line whose declination angle is larger than 45 degrees and smaller than 45 degrees.Recognition of the short line and the symbols of the end points on the line is also studied.