Abstract:A flow field control system is designed to meet the requirement of aerodynamic performance test for the flapping wing aircraft. Based on the hardware of PLC and converter, a cascade control system composed of a motor speed loop and a wind speed loop is given. And in order to improve the fast response,the motor speed feedforwad method is proposed. Due to the reasonable control regulator and feedforward function,the flow field control has achieved a good result. The test results show that the precision of motor speed is superior to 0.2%, the precision of wind speed is superior to 0.2m/s, the system has smooth adjustment process and good disturbance rejection. The system has been applied successfully to the aerodynamic performance test for the flapping wing aircraft.