On the basis of metal cutting and rigid-plastic finite element theories, taking cutting force in turning process as the research object, a FEA model for turning process using a MDT cutter on a centre lathe CA6140 is constructed to simulate its metal cutting process. Using Deform 3D, cutting forces are calculated according to different cutting parameters. The influences of the cutting parameters on the cutting forces are investigated. In order to validate the FEA model, cutting experiments are conducted. Comparison between simulated cutting forces and experimental forces shows similar trends and reasonable agreement.