Aiming at an independent developed fiveaxis ultrasonic equipment, through the indepth study of multiaxis motion relation, control systems,ultrasonic mechanism, dedicated ultrasonic tools,and tool trajectories of the equipment,a set of postprocessing algorithms suitable for this ultrasonic equipment was obtained. Based on Visual Studio 2010 development platform, a dedicate post processing system was developed using C# language. A typical largescale multidegreeoffreedom surface part of C919 was selected for application verification. The results show that the algorithm and system are stable and can meet the actual needs, and have strong applicability and promotion.