The invention provides an assistance manipulator and a control system thereof. The assistance manipulator comprises a fixed stand column, a rotating joint, a rotating stand column, a balance cylinder, a parallelogram mechanism, a trajectory self-balance machine 6, a swing joint, a terminal actuation mechanism, a fixture, and a control system. When a force arm at one end of the assistance manipulator is changed, a force arm at the other end is also changed, and a fixed proportional relation is kept, so that a counter force is always balanced with a reaction arm no matter high-low motion, left-right motion and rotating motion of workpieces, the workpieces are always located in a floating state, the gravity is overcome, and the assistance function is realized. The assistance manipulator realizes floating of objects through combined application of the force balance self-adaption and the pneumatic principle, performs zero-gravity carrying and assembly for the objects, realizes hoisting, plane movement and overturning of weights through micro force of human hands, and is smooth and balanced in the motion process.