In order to improving the takeoff performance of unmanned aerial vehicles (UAVs) under high elevation environment, the stud-ies of flow control over a wing with high aspect ratio using a single symmetrical layout of dielectric barrier discharge plasma actuator were carried out with the help of wind tunnel experiments and numerical simulation at low Reynolds number. The flow control effect was evaluated and the flow control mechanism was revealed. Interestingly, the laminar trailing edge separation vortex and the stall separation flow can be suppressed by one symmetrical plasma actuator. Initially, the results indicated that the variation of wing aerodynamics with angle of attack conforms to the characteristics of low Reynolds number aerodynamics at the Reynolds number of 7.47 × 104. The lift coefficient increases nonlinearly, while the drag coefficient first increases, then de-creases, and then increases again. It should be noted that the trailing edge separation vortex is the underlying mechanism of non-linear aerodynamic phenomena. In addition, the aerodynamic performances of wing can be enhanced by the symmetrical plasma actuator over a wide range of angles of attack. At low angles of attack, the phenomena of aerodynamic nonlinearity were elimi-nated almost and the maximum lift to drag ratio was increased by about 15% by the plasma actuator. At high angles of attack, stall separation flow around the wing was suppressed and the stall angle is delayed by about 3 °. Meanwhile, the induced vortices of symmetrical plasma actuator play an important role in achieving flow control over a wide range of angles of attack. The in-duced vortices transferred the momentum from the leading edge to the trailing edge of airfoil and squeezed the laminar separa-tion bubble when controlling the trailing edge separation vortex at low angles of attack. On the other hand, the induced vortices enhanced the mixing between high-energy mainstream and low-energy boundary layer airflow and suppressed the stall separa-tion flow by integrating the large-scale separation vortices at high angles of attack.