Abstract: The topological relationship is prone to appear inconsistent phenomenon in the incremental updating of urban dual-carriageway roads. Aiming at the problem of topological conflict detection and processing between single- and dual-carriageway roads, A new topological conflict detection and processing method based on extended polyline-polygon four-intersection model is proposed. Firstly, we discuss possible topological relation types and expression between single-and double-carriageway roads. Then, a spatial relation expression model including the relation between polyline and polygon, the number of common intersections and whether it is the vertex of dual-carriageway roads is designed. Finally, the topological conflict types are determined by calculating the matrix difference between the correct topological relation and the updated topological relation of single- and carriageway-roads, and the corresponding topological conflict processing rules are constructed. An experimental results shows that the method can effectively express the topological relationship between single- and dual-carriageway roads and do the work of topological conflict detection and processing very well with good pertinence and precision.