The invention relates to a wearable elbow joint rehabilitation robot device, wherein an upper arm bracket is movably connected with a lower arm bracket, such that the lower arm bracket can rotate around a hinge center, the insides of the movable hinge joints of the upper arm bracket and the lower arm bracket are connected with a driving motor and a lithium battery through a spacing bar, the outsides thereof are connected with a driven chain wheel to rotate the lower arm bracket around the hinge joints, the output shafts of the driving motor are provided with a driving chain wheel which is connected with the driven chain wheel through chains to drive the lower arm bracket to perform circling motion around the hinge center, the driving motor is arranged outside the upper arm bracket and the lower arm bracket to enlarge the motion range of the elbow joint and balance the weights of the upper and lower arms of the patient. The wearable elbow joint rehabilitation robot device has the advantages of simple structure, small size and portability, only the lithium battery is charged, the robot device can be used for training at any time and place without restriction and has multiple control manners and training modes. The robot device can be used for passive training and active training under electromyographic control, muscle force is easily trained only by clicking the mobile phone touch screen or the voice control.