The invention discloses an ultrasonic inserting cutting tool for processing a curve outline of a honeycomb core. The ultrasonic inserting cutting tool comprises a threaded section, a rigidity improving block, a trapezoid-like shaped platform transition block and a thin-sheet shaped open type tool body, wherein axes of the threaded section, the rigidity improving block, the trapezoid-like shaped platform transition block and the thin-sheet shaped open type tool body are positioned on an axis of the ultrasonic inserting cutting tool for processing the curve outline of the honeycomb core. According to the ultrasonic inserting cutting tool for processing the curve outline of the honeycomb core, the curve outline of the honeycomb core material is inserted and cut under ultrasonic vibration effect; the honeycomb core material can be smoothly cut through a circular arc shaped cutting bottom edge under the ultrasonic effect, thus the damage of the honeycomb core material in processing can be decreased, and the processing rigidity of the rest materials can be improved; in addition, the friction between the circular arc shaped cutting bottom edge and the processing surface of the honeycomb core is reduced by the ultrasonic effect, so that the processing defects of the curve outline of the honeycomb core can be reduced; the abrasion of the tool is reduced, and as a result, the service life of the tool is prolonged; and the curve outline of the honeycomb core is processed with high quality.