Using numerical simulation methods, the influence of plasma aerodynamic actuator on the flow characteristics of film cooling under coolant crossflow condition is explored based on the established plasma aerodynamic actuator model. The variation law of film cooling efficiency is obtained. The results show that there are four vortices near the outlet of the film cooling hole, originating from the streamwise vorticity of the boundary layer inside the film cooling hole and the shear effect between the main flow and the jet flow. The size, strength, and evolution process of the vortices are affected by the coolant crossflow channel Reynolds number and blowing ratio. After applying plasma excitation, a new pair of vortices of which the rotating direction is opposite to the counter-rotating vortex pair is formed, the wall attachment of jet is enhanced and spanwise expansion capacity of jet flow is strengthened, thus the film cooling effectiveness is improved. The plasma aerodynamic actuator has little effect on the discharge coefficient. The film cooling effectiveness under coolant crossflow condition is higher with low Reynolds number when the blow ratio is less than 1.0 while the film cooling effectiveness is higher with high Reynolds number when the blow ratio is larger than 1.0.