Abstract: A 3D model of quadrupole magnetic ring constructed by AutoCAD is proposed to improve design and R&D efficiency of quadrupole magnetic ring for automobile micromotor. Finite element analysis method by Ansoft Maxwell is employed to conduct numerical simulation of distribution of the surface radial magnetic flux density of anisotropic bonded NdFeB quadrupole magnet ring. The influences of remanence B_r, coercive force H_cband the height, thickness and inner and outer diameters of magnet rings of anisotropic bonded NdFeB on the magnetic flux density and magnetic properties are investigated.Results show that the surface radial magnetic flux density of magnet rings is significantly affected by the coercive force H_cbof NdFeB and the thickness of the magnet rings, while slightly affected by remanence B_rand the height of the magnet rings.