Abstract: In this paper, a model of self-excited aerodynamic forces acting on a section of bridge deck with additional airfoil attached below the trailing edge is established. A suspension bridge project is taken as an example, in which the evolution of critical wind speed of flutter during bridge erection is studied by a multi-mode flutter analysis approach. With the most dangerous construction stage as an example, the effectiveness of the airfoil in the flutter stability of the system is investigated. The analysis shows that the additional airfoil attached below the trailing edge of bridge deck is an effective aerodynamic means for suppressing the flutter of the suspension bridge during erection.