Abstract: The underfloor wheelsets lathe is a critical facility for online processing of locomotive wheels. It has a direct effect on wheel tread’s stability for the change of turning parameters in the turning process. First, based on the dynamic turning forcebeingexcitation, a dynamical model of the turning system was established and analyzed to confirm the influence factors of turning stability for underfloor wheelset tread’s process. Second, reasonable inference was also made and the correction of the model was verified in this paper. Fianlly, through example simulation, the spindle speed, rigidity coefficient and tooling geometric parameters were obtained to be crucial for turning chatter system stability. Results show that the stability of turning processing can be effectively controlled by adjusting these parameters to improve the efficiency and precision.