Abstract: The machining process of large-scale aluminum alloy ring forgings is complicated with many processes, and the deformation of workpiece is accompanied in the machining process. Aiming at the deformation problems caused by each main process, the deformation mechanism is deeply studied in combination with the technology of machining and the properties of workpiece materials. Focusing on the causes of deformation, a series of deformation control measures are put forward before, during and after processing. The validity of the deformation control method is verified by experiments, which provides a reference for process optimization of subsequent mass production of workpieces.