Plasma flow control has potential applications in shock wave control for improving aircraft/thruster performance obviously. Numerical simulation of plasma aerodynamic actuation reducing transonic drag of RAE2822 airfoil was presented. Based on phenomenological modeling viewpoint, the discharge plasma aerodynamic actuation was simplified as thermal energy injection into flow, which was initialized from experimental data and added in the flow N-S equation as thermal source term. The effect of plasma aerodynamic actuation on the airfoil drag characteristic was investigated under different conditions. The results show that plasma aerodynamic actuation can reduce airfoil transonic drag availability. The drag reduction depended on the freestream parameters, which was 13.58% at Ma=0.81. The drag reduction responded to source term temperature rarely, which was 11.77% at W=3 000 K. The drag reduction responded to the distance between the location of plasma actuation and shock wave, which was 13.17% at D=20 mm.