The invention discloses a magnetorheological damper with annular and disc-shaped liquid flow resistance channels simultaneously, which comprises a damper cylinder body (4), a piston rod (16), a piston head (28), an upper end cover (14) and a lower end cover (29), wherein the piston head (28) comprises a magnet exciting coil (9), a magnet exciting coil rack (10), a valve core (24) with a longitudinal central through hole (27), a valve core outer cover (8), discs (13) symmetrically arranged outside the two end faces of the valve core (24), a disc-shaped liquid flow resistance channel (11) formed by the end face, which is opposite to the valve core (24), of the discs (13) and the end face corresponding to the valve core (24), and an annular liquid flow resistance channel (12) formed by the circumferential surfaces of the discs (13) and the inner circumferential surface of the valve core outer cover (8); the magnet exciting coil (9) and the valve core (24) belong to an internal magnetic circuit with a magnetic field; the magnetic field begins with the valve core (24), passes through the disc-shaped liquid flow resistance channel (11), the discs (13) and the annular liquid flow resistance channel (12), passes through the annular liquid flow resistance channel (12), the discs (13) and the disc-shaped liquid flow resistance channel (11) along the valve core outer cover (8) and is closed at the position of the valve core (24); and the valve core outer cover (8) can be disassembled from the piston head (28). The damper provided by the invention has the advantages of high efficiency, wide damping force dynamic range, simple structure, small volume and the like.