Intersection polygons are an important component of road data. To address the challenge of extracting the microstructure of roads, we propose a method of extracting intersection polygons based on centerline junctions. The method involves the following steps: (1) topological preprocessing of the road centerline to extract dangling nodes and converting road polygon data into line rings, (2) matching the nearest line ring within a certain threshold range of dangling nodes to obtain splitting points, (3) calculating the set of splitting points associated with the line rings and dividing the line rings to obtain boundary arcs, (4) extracting the boundary arcs associated with the current intersection from the intersection nodes of the road centerline, and (5) calculating the primary nearest point set and the secondary nearest point set in turn, and using the secondary nearest point set to extract the resulting intersection polygons. Experimental results indicate that the method can effectively generate the required intersection polygons at road intersections.