Aiming at the problem of high eddy current loss of in-wheel permanent magnet synchronous motor with high power density,a kind of surface mounted permanent magnet synchronous motor with novel magnetic pole structure is designed. The outer arcs of magnetic pole is eccentric and the inner and outer arcs have different arcs. The influence of the new eccentric magnetic pole structure on air gap flux density and eddy current loss is analyzed by analytical method. The 10-pole / 12-slot three-dimensional motor model is built in the finite element software to simulate the electromagnetic and steady-state temperature fields. The results show that the eddy current loss of permanent magnet per cubic centimeter is reduced by 17. 20% and the steady-state temperature of permanent magnet is reduced by 3 ℃ , therefore, the structureimproves the running performance of in-wheel permanent magnet synchronous motor.