With the application of explicit dynamics and probability finite element method, reliability virtual experiment of deep groove ball bearing is carried out. Based on self –adaptive mesh module of the ANSYS/LS-DYNA, true numerical simulation of the working process is presented after the three-dimensional finite element bearing model is built. Then, the contact stress and strain among balls, retainer and inner (outer) race and also the pressure law during the contact process are obtained. As the randomness of manufacture and assemblage tolerance is inevitable, Monte Carlo method is adopted when samples the bearing system. From the random sampling, a large sample data of the maximum contact stress is got and the reliability coefficient is calculated; and the contribution of each original manufacture error to the reliability sensitivity of the bearing is analyzed. Reliability virtual experiment offers a theoretical reference to fatigue strength calculation and dynamic optimum design of the bearing system, and the analysis process is easy to be program controlled.