Using the RNG κ-ε two-order precision enhanced wall function method, the changes of flow field characteristics and aerodynamic coefficients of a fanwing airfoil are numérically simulated at different angles of attack, fan speeds and flow velocities. The analysis of the flow field shows that: In the condition of large flow velocity, the blade on the top fan airfoil causes the separation of airfoil flow; with the increase of velocity, the flow separation increases, and the fan airfoil lift coefficient caused by the flow separation decreases with the increase of flow velocity. Through the study on the variation of aerodynamic coefficients of distributed points on the chord line with the angle of attack, the flow velocity and the fan speed, it is sure that the points that donot change with the aerodynamic coefficients are on the 40% of chord length from the leading edge airfoil.