A new method named mixed fast multipole boundary element (MFM-BEM) is introduced in this paper to solve the contact problem of mill roller bearing. Incompatible elements and compatible elements are used to construct shape functions in non-contact area and contact area. On the one hand, MFM-BEM avoids satisfying the conditions of precise coordination in compatible elements, on the other hand, this method retains the merits of fast multipole boundary element method (FM-BEM). Through numerical examples, it clearly demonstrates that the calculation time and accuracy are improved. MFM-BEM provides an efficient numerical method for designing and analyzing the mill roller bearing. It also provides theoretical basis for prolonging mill roller bearing service life.