Solar panels and satellite antennas on spacecraft are coupled systems with multiple flexible bodies. Multiple flexible coupling structures have the characteristics of close modes， low stiffness， and small damping； they are easily excited by disturbances to produce long-lasting and large amplitude coupled beat vibrations. To study the active vibration suppression and anti-disturbance ability of coupled multi-flexible structures， aiming at a three-coupled flexible beam （TCFB） system， the machine vision is used for vibration detection and feedback， and a nonlinear H_∞ control method is used for vibration control. A three-coupling flexible piezoelectric beam experimental platform is established based on visual inspection and spring connection. The finite element model is established， and the parameters of the model are corrected according to the excitation identification of the free vibration and sinusoidal response signals. The anti-disturbance index is given based on the H_∞ algorithm. By using the identified finite element model and the designed nonlinear control law， the H_∞ controller is obtained based on the anti-disturbance， control speed， and energy consumption indices. The experimental study of disturbance vibration control based on visual feedback is carried out. The experimental results show that the vibration suppression speed of the H_∞ control is approximately the same as that of the PD control， but the vibration amplitude of the H_∞ control is lower when the vibration is stable. The experimental results indicate that the H_∞ control method has better anti-disturbance ability than the PD control method.