By taking wheel groove milling machine spindle as the research object, the 3-D finite element model (FEM) of the spindle was established by using the APDL language. The force distribution of spindle during processing was calculated with analysis, and the deformation nephogram of the spindle was obtained. At the same time, by taking the bearing stiffness, load and Modulus of elasticity as random input parameters, the Monte Carlo method based on Latin hypercube sampling was applied to the spindles reliability analysis. The results showed that the 500 times loop simulation can meet the accuracy requirements, groove milling machine spindle's reliability is 100%, and lessened dispersed material parameters can improve the reliability of spindle.