The invention discloses a flexible driver with controllable damping and used for a
robot joint. The existing flexible driver is
lag in drive response, and uncontrollable in flexibility. The inner ringof a hollow rotary platform of the flexible driver disclosed by the invention is driven by an external force, and drives an electric
brush rotor and an output disc to rotate; an inner rotary disc comprises a disc body and a central stud; the inner ring of a planar torsional spring is fixed to an output disc, and the outer ring of the planar torsional spring is fixed to a cross support frame and the disc body; an outer rotary disc is born on the central stud, and compressed with an end surface opposite to the disc body, and a compression force is adjusted by an adjustment device; 2-4 grooves are formed in a part close to the edge, of the disc body; a
magnetorheological fluid is injected into each groove;
two fluid through holes are formed in the bottom of each groove, and the outer ends ofthe
two fluid through holes are communicated by a pipeline; each pipeline is wound with a coil; and cylindrical bodies as many as the grooves are arranged on the inner end surface of the outer rotarydisc, and each cylindrical body is embedded in the corresponding groove and divides the groove into two cavities. The flexibility of the flexible driver disclosed by the invention is effectively improved, and a controllable movement flexibility degree is achieved.