Problem reports and change control are two basic requirements of DO-178C for the configuration management activities of civil aircraft airborne software, and change impact analysis has always been a difficult issue in airborne software change control procedure. Incomplete analysis of the impact of changes may cause abnormal operation of affected software components, and the impact on the safety of military and civilian aircraft onboard equipment cannot be ignored. In order to quickly and effectively allocate the change impacts on other software units and on related software life cycle data, this article uses directed graphs to abstract the coupling relation between software units, and digitalizes and stores data structures related to vertexes and edges design in directed graphs. Reverse search is used to traverse the directed graph data, quickly quantifying the potential impact of original software changes.