The self-tuning proportional integral differential (PID) controller by particle swarm optimization (PSO) is presented to suppress the vibration of the piezoelectric flexible manipulator during its operation. With the integrated time and absolute error (ITAE) criterion as the fitness function, the three parameters Kp , Ki and Kd of the PID controller are adjusted using normal PSO. A Simulink model for vibration control of the two-link piezoelectric flexible manipulator is established in the Matlab Simulink program. An experimental system of flexible manipulator for vibration control is developed with virtual instrument technology. The simulation and experimental results show that both the traditional PID controller and PID controller tuned by PSO can effectively restrain the elastic vibration of the flexible manipulator, but the latter shows better inhibitory effect, robustness and stability compared with the former.