Compared with traditional 5-axis machining, ultrasonic cutting adds a sixth servo axis that controls the cutting direction of the tool in real time, which makes its cutting motion, material removal method and process programming method significantly different from that of traditional cutting machining. Aiming at the problem of difficulty in programming ultrasonic CNC machining of aerospace honeycomb core parts due to the special machining process of non-standard tools, a CNC machining programming method for honeycomb core parts based on feature recognition is proposed. The geometric and topological information of honeycomb core parts is extracted, the low-level data model is transformed into high-level features by logic rules, the machining steps of features are generated by knowledge-based process decision-making, and the process route is formed by combining with the process route rule base to ultimately realize the generation of toolpath. The integration of aerospace honeycomb core part CAD/CAPP/CAM is realized using the NX12.0 and VS2015 secondary development system interfaces.