摘要:Wear and deformation CNC grinding machine tool, will be aggravated over time ofwhich will influence the manufacturing precision. To reduce the effect, the soft compensation method by modifying NC instruction was put forward to maintain the manufacturing precision of CNC crankshaft grinding machine tool. The error sources were analyzed, the errors caused by grinding force were calculated, and the precise grinding kinematics model was deduced by the multibody kinematics. Numerical simulation and manufacturing experiment were carried out and the rank tests were taken for the manufactured crankshafts. Experiments show that the manufacturer precision of the crank can be enhanced by 63.69%, 52.06%, 42.27%, and 30.96% by soft compensation of 10 years of service life and 10 μm grinding depth, 4 years of service life and 10 μm grinding depth, 10 years ofservice life and 6 μm grinding depth, and 4 years of service life and 6 μm grinding depth, respectively. Soft compensation can be applied to the machine tool in which the manufacturer precision has declined and the NC instruction with compensation should be updated periodically.