The transmission performance based on magnetically coupled resonant wireless power transmission (MCR-WPT) mainly depends on the quality factor of the system and the constraint on the magnetic field lines. This paper first introduced the expression of quality factor of system after adding the core in the coil and analyzed it. Then simulate the magnetic fields generated by the coil after adding Mn-Zn ferrite in Maxwell software. Through experiments and final processing of the data concluded that after adding Mn-Zn ferrite coil, the transmission efficiency of wireless power transmission system has been significantly improved.