The utility model relates to an electromagnetic internal drive torque power mechanism which comprises an outer shell, an inner shell, an inner shell, an outer shell and an inner shell, the excitationstator is sleeved on the connecting part; the eccentric sleeve is coaxially and rotationally arranged on the connecting part in a sleeving manner; the end, provided with the inner gear ring, of the output flange coaxially sleeves the connecting part, and the output flange is rotationally connected with the inner wall of the shell; the swing gear rotor comprises a first swing outer gear and a second swing outer gear which are coaxial and different in tooth number, the outer diameter of the second swing outer gear is smaller than that of the first swing outer gear, the second swing outer gear rotationally sleeves the outer ring of the eccentric sleeve, the second swing outer gear is meshed with the output flange inner gear ring, and the tooth number of the second swing outer gear is smallerthan that of the output flange inner gear ring; the magnet is coaxially fixed on the inner wall of the first swinging outer gear; a second gear ring meshed with the first swinging outer gear is arranged on the inner wall of the shell and is coaxial with the connecting part, and the tooth number of the second gear ring is larger than that of the first swinging outer gear. The advantages are that low-rotating-speed large-torque output can be realized.