Comparing with manned planes, the actuator systems of unmanned aerial vehicle are requested to realize same function with smaller place,which needs actuators to be more smarter and compact. A newtype compact flexible actuator was proposed in which PMSM was used to drive two plungers to drain and suck oil. The oil was distributed via directional valve. The actuator was integrated into shell,so the actuator's volume was decreased. The actuator's servo control loop was also designed. How to configure PI parameter in rate loop and current loop was demonstrated. With building simulation model to drive mass load,it is proved that the actuator dose well in response rate,dynamic performance and load capacity.