The utility model discloses a controllable overrunning clutch, which comprises an outer ring, an isolating ring, an inner ring, an eccentric cam, a stop plate and a roller, wherein the expanded multi-planar inner ring is sleeved in the cylindrical outer ring, the inner circle of the outer ring and the outer planes of the inner ring form a wedge-shaped space, the isolating ring sleeved on the inner ring is arranged at the left side of the outer ring, an arc-shaped holding frame extends from the isolating ring to one side of the outer ring, the holding frame penetrates in the wedge-shaped space formed by the outer ring and the inner ring, the roller is arranged in the holding frame, the circumferential matching surfaces of the holding frame and the roller are arc-shaped surfaces, and the roller is arranged at a position of the wedge-shaped space, which is opposite to the plane on the outer circumference of the inner ring; and the eccentric cam sleeved outside the inner ring is arranged at the left side of the isolating ring, and the stop plate sleeved outside the inner ring is arranged at the left side of the eccentric cam. The controllable overrunning clutch has the advantages of reliability, accuracy in timing action, large transmitting torque, sensitive switching transient response and the like.