Abstract: In the industry, it′s the first time that a large conical integral thin-walled shell was adopted cnc manufacturing method using integral forging. In the process of machining, the main problems are complicated structure, high precision requirements, high material removal rate and difficulty in prcessing defommation control. Through analyzing the features of the workpiece, this paper degigns a reasonable tuming-milling processing plan, which realizes the effective clamping, stress change control and compensation processing of the shell workpicce, and ensures the design requirements of the finished workpiece.