The invention discloses an auxiliary rehabilitation exercise device for realizing finger rehabilitation exercise. The device comprises a bracket and a finger support arranged on the bracket. One end of the bracket is provided with a first shaft, and one end of the first shaft is connected with a motor; the other end of the bracket is provided with a second shaft, one end of the second shaft is connected with a magnetorheological fluid damper, and the other end of the second shaft is connected with the other end of the first shaft by a spring; the finger support is fixed on the second shaft, the second shaft is also provided with an angular transducer for measuring angular displacement of the second shaft and a force transducer for measuring torque of the second shaft. Compared with the prior art, the device combines active and passive finger rehabilitation exercises, is especially suitable for the rehabilitation exercise of single wounded finger. Meanwhile, the device has simple and compact structure and low machining precision requirement.