Skyline query processing is essential for the database community. Many algorithms have been designed to reduce dominance tests between multidimensional points to achieve efficient computation, where incomparability between points has been considered an important property to avoid unnecessary dominance tests. We present a new approach based on subset queries to integrate a pre-check of incomparability for sorting-based skyline algorithms, which can significantly reduce the number of dominance tests in order to accelerate existing algorithms in large datasets.