In the multiaxis synchronous system, the main objective of synchronous control is to reduce the synchronous error and tracking error. Firstly, to solve the problem of traditional relative coupling control in practice, an improved relative coupling control structure is proposed. The virtual master axis is added in the structure. While referring to the feedback speed of each axis, the virtual master axis synchronously completes the given compensation of the speed of each axis. The synchronous control performance is optimized and the speed compensation structure is simplified. Secondly, combined with the fuzzy compensation, the adaptive correction of control parameters is realized. Finally, the experiment of the mechanism is carried out. The results show that, compared with traditional relative coupling control structure, the proposed control method can simplify system structure and improve synchronous performance, and the tracking error can be reduced obviously in the load disturbance circumstance. The proposed method provide a reference value in the synchronous system.