The optical interference technology was used to observe the changes of the surface dimple under zero entrainment velocity condition and different starvation.A balldisk wear testing machine was used to study the damage behaviors of 45 steel in the oppositesliding condition and the effect of working time,surface velocity and load on the wear of 45 steel.The results show that under zero entrainment velocity condition,the oil starvation will lead to the disappearance of the oil film dimple,which will increase the contact and wear of the metal surface.In the oppositesliding condition,the contact condition is aggravated with the increase of the oil starvation,and the wear in dry contact is the severest for the same working time.The increase of working time,load and surface velocity will aggravate the wear.The main wear mechanism is fatigue wear and adhesive wear.