Aircraft casing parts are usually made of aviation difficult-to-cut materials, which are difficult to cut, characterized with such flaws as thin-walled texture, poor rigidity, cutting difficulty, and tendency to cutting deformation. Therefore, with the aviation thin-walled casing parts as the research object, based on dynamic cutting force modeling, a prediction can be achieved of the turning deformation of thin-walled casing parts by adopting the finite element analysis method. On this basis, the active deformation compensation method is used for the reduction of the machining deformation by compensating the cutting depth of each tool pass. The results of both the finite element simulation and cutting tests show that this method helps to greatly reduce the machining deformation error after compensation, and make its distribution more uniform, thus effectively controlling the cutting deformation.