Abstract: The support frame is a device for placing and launching missiles. Its inner hole is a deep hole structure composed of five rib plates. Because of the particularity of its structure, the traditional deep hole processing method is difficult to complete. Therefore, based on the full analysis of the technical difficulties in the processing process, this paper puts forward three solutions: Design of special fixture, improvement of alignment method and improvement of deep hole boring cutter, Finally, the reasonable processing technology is determined, which successfully solves the problem of deep hole intermittent cutting instability, only guarantees the machining accuracy and surface quality of the inner hole, improves the loading efficiency and service life of the support frame, and reduces the use risk.