By analyzing the information obtained from the operators and each processing stage of the load-bearing frame made of titanium alloy for a certain type of aircraft, we optimize the machining process and NC programs of the part on the base of the factors which restrict processing efficiency. When dealing with the process of machining the fillets of the part, we get the plunge milling method with numbers of tests, which solves the problem of breakage of the milling cutter. By the use of indexable end milling cutter, we get the recipe for the trouble of fracture of cutting tools by the reason of uneven allowance when machining the reference surface and improve the efficiency at the same time. All of these will offer valuable experience for the machining process of similar parts.