In this paper, according to the design parameters, the design scheme and simulation analysis of the double air-gap field modulation permanent magnet motor are completed. The main feature of this motor type is that the permanent magnet gear and permanent magnet motor are combined on both electromagnetic and mechanical dimensions, incorporating two rotors and dual air gaps. And the magnetic field modulation effect is adopted to convert the small torque of the less-pole rotor to the large torque output of the more-pole rotor, which is especially suitable for the low speed large torque application. The operational principle of the motor is declared, moreover, the electromagnetic properties including both static and transient properties are analyzed and calculated by finite elements method. And the performance parameters meet the design requirements.