Abstract: Bridges and winds are fluid-solid interacting coupling systems. The effects of wind on bridge systems can be divided into damping effects and stiffness effects. Firstly, based on the principle of energy equivalence, the Scanlan linear flutter self-excitation is divided into pure damping effect term H₁^*、A₂^*, pure stiffness effect term A₃^*、H₄^*, and double effect term A₁^*、H₂^*、H₃^*、A₄^* with both stiffness and damping effect. The flutter self-excitation is integrated to calculate the reactive time history of the damping effect term and the stiffness effect term. The classical coupling flutter driving mechanism is studied from the functional point of view. The differential equation is transformed into a functional equation form. Moreover, and a flutter derivative identification method based on self-excited instantaneous work is proposed and the reliability of the method is proved.