Abstract: Using an custom-made optical interferometry system which can simulate the motion of a thrust ball bearing, the waviness on the raceway of the housing washer was obtained by the Hertzian contact theory, and the variation of oil film thickness in one revolution of the ball-glass contacts was measured. Based on the experimental parameters, elastohydrodynamic lubrication calculations were carried out to theoretically reproduce the contacts between the balls and the glass as well as those between the balls and the raceway. Both experiments and theoretical analyses verified the influence of the waviness on lubrication state and proved that the variation of the oil film in the thrust bearing's motion was related closely to the surface waviness on the raceway.