Abstract: In view of problems existed in current algorithm of automatic generation of double-line laneway, the paper proposed a new algorithm of automatic generation of double-line laneway based on centerline. The principle of the algorithm is as follows: offsetting 1/2 of laneway width from laneway centerline to both sides to generate double-line laneways with different widths, connecting initial and ending of the double-line to form polygon area; selecting two laneways arbitrarily, finding intersection points of polygon area of one laneway and double-line of another laneway and judging whether double-line between two adjacent points is in region of the polygon area, if it is in the region and one laneway is above another laneway or both laneways are interpenetrate, then clipping the double-line laneway; traversing and processing all laneways by use of the above method, which can generate interpenetrate or crossed double-line laneway graph.