In this paper,  an outer rotor electric bike brushless DC motor of 200 KW for Electric Vehicle is investigated with different magnet topology. Magnetic angle and Halbach arragement are varied to evaludate their electromagnetic torqur, forces and temperature distribution. The power and torque density and efficiency performance have been also studied and compared with IPM motor with the same geometry and power drives. This study for applying an auto-design program is to find out suitable permanent magnetic parameters and winding size after iterations. This program allows to estimate the magnetic flux density, electromagnetic torque, and ripple torque via a finite element magnetic method (FEMM). In order to reduce the cogging torque ripple and harmonic order of Back EMF, the magnet angle and halbach topology will be validated by the FEM simulation. The simulated results is also compared with  the measured results from the experimental test system.