The invention discloses a magnetorheological clutch with the small size and the large controllable range. The magnetorheological clutch comprises a shell body, a driving mechanism and a driven mechanism; the driving mechanism comprises an input shaft, an input disc and a permanent magnet, and the permanent magnet is arranged between the input disc and the input shaft; the driven mechanism comprises an output shaft, an output disc and a connecting cylinder; the output disc comprises two or more output disc bodies, the output disc body at the bottommost end is fixedly mounted on the output shaftin a sleeving mode, the outer edges of all the output disc bodies are connected into a whole through the connecting cylinder, and an airtight annular liquid storage cavity is formed between the output disc body at the topmost end and the output disc body at the bottommost end; the annular liquid storage cavity is filled with magnetorheological liquid; an annular storage cavity is formed between the every two adjacent output disc bodies, and each output disc body is located in the corresponding annular storage cavity; and an inner liquid storage cavity is formed in the input disc, a magnet exciting coil is further arranged in the shell body, and the magnet exciting coil surrounds outside the connecting cylinder. The magnetorheological clutch has the advantage that the purpose that passivetorque is small enough during no current excitation is achieved.