Based on the phenomenology model of plasma aerodynamic actuation, a macroscopic effect of plasma aerodynamic actuation on fluid is equivalent to body force vector. Mechanism analysis of the effect rule of plasma aerodynamic actuation on 2D film cooling is studied by coupled solution of body force with Navier Stokes equation. The results show that after the cool flow is subject to the plasma aerodynamic actuation near the wall at the exit of film slot, the horizontal velocity component increases greatly while the vertical velocity component gains a little. When the blow ratio increases, the momentum and flux of cool flow and the film cooling effectiveness increase, while the influence of plasma aerodynamic actuation on cooling flow and the increment of film cooling effectiveness decrease. Under the plasma aerodynamic actuation, the film cooling effectiveness decreases when film slot inclination angle increases at each blow ratio. Plasma aerodynamic actuation body force has large impact on film cooling effectiveness, the film cooling effectiveness increases and then decreases with the increase of magnitude of body force, there exists an optimal body force magnitude.