The parameters′randomness-stiffness, damping, and cutting force of the turning system strongly impact the stability of a computer numerical control (CNC) lathe. This paper proposes a method for reliability analysis of the regenerative chatter stability of the CNC lathe. The statistical distribution of the regenerative chatter stability is studied using the Monte Carlo simulation (MCS) method. First, the dynamic model of turning regenerative chatter is established, and the limit cutting width of machining and its responding rotation speed of the spindle are obtained using Laplace transform. Then, the experimental samples are selected according to the distribution information of the turning system′s random parameters. Samples of the limit cutting width and their statistical features are derived from the dynamic model of regenerative chatter. Finally, an MCS method for predicting the reliability of the stability of CNC lathing is proposed based on the criterion of whether the actual cutting width is less than the limit cutting width.