Abstract: Polygon decomposition has been widely employed in the fields of computer graphics, CAD software, and path planning. The presence of self-intersections in polygons introduces errors and inaccuracies in subsequent computations and drawing operations. Decomposing self-intersecting polygons poses a common challenge in CAD applications. Traditional algorithms rely on triangulation techniques. However, this approach yields a substantial number of triangles, significantly elevating both computational and storage complexities. In response to the issue of self-intersecting polygon decomposition, a decomposition algorithm based on region partitioning is proposed. The approach begins by identifying all intersection points within the polygon. Then, a pathfinding technique is employed to traverse the self-intersecting polygon, partitioning it into non-overlapping and self-intersection-free regions. Finally, by discerning the inclusion of each region, internal areas are preserved, while external ones are discarded. This process results in a decomposition of the self-intersecting polygon into non-overlapping simple polygons. Comparative experiments with the GluTess method on large integrated circuit boards reveal that our algorithm improves time efficiency by around 60% and reduces spatial occupancy by about 20%.