The invention belongs to the technical field of damper products, and particularly relates to a magneto-rheological torsion damper. The magneto-rheological torsion damper comprises a base, a rotor assembly, a stator assembly and an electromagnetic coil, wherein the rotor assembly, the stator assembly and the electromagnetic coil are sequentially installed on the base from inside to outside; the stator assembly comprises a cylindrical annular stator body, an upper cover plate and a lower cover plate arranged on and under the stator body, and a separation block arranged inside the stator body; the stator body, the upper cover plate and the lower cover plate define a liquid cavity filled with magneto-rheological fluid; the separation block divides the liquid cavity into a left liquid chamber and a right liquid chamber; a magneto-rheological passage communicating with the left liquid chamber and the right liquid chamber is arranged in the separation block; and the rotor assembly comprises arotary shaft and a separating plate which are designed integrally. The damper can adjust damping force continuously within a large range, is good in sealing performance, is free of oil leakage, is not affected by magneto-rheological fluid sedimentation, and is good in damping effect.