Mill Roller bearing is made up of internal ring,middle rolls and external ring,which belongs to multi bodies contact problem.So it is rather difficult and complex to analyze load peculiarities of mill roller bearing directly.In this paper,based on three dimensional elastic contact BEM,it is introduced that middle rolling bodies can be described as plate units,placed on the internal ring,therefore the contact problem can be changed from multi bodies to two bodies.As the elastic deformation of plate unit,it can be calculated by Hertz contact formula and is regarded as a gap to be substituted to the total matrix equality,so the three dimensional distribution of load peculiarities of mill roller bearing can be achieved.The calculating model of this method is visualized and simple, and has higher accuracy,therefore it become effective numerical method to design and analyze load peculiarities of mill roller bearing.