The research on active flutter control of functionally graded material structures is of great significance to improve the safety and stability of aerospace systems. Therefore, the purpose of this study is to analyze the active flutter control of functionally graded irregular plates (FGIP) by attaching piezoelectric layers to their surfaces. Firstly, a discrete-coupled modeling method for irregular panel structures is proposed. The main modeling idea is to discretize the whole structure and calculate the energy expression of the discretized individuals. Then, the adjacent individuals are coupled by artificial springs. Finally, the dynamic model of irregular panel structure is established based on the Hamilton principle. The validity of this modeling method is verified by comparing the results with the natural characteristics of the finite element model. The first-order supersonic piston theory is used to calculate aerodynamic pressure, and the flutter characteristics of FGIP under supersonic airflow are analyzed. In addition, the influence of the power law index of functionally graded materials on structural flutter characteristics is discussed. To suppress the flutter of FGIP, the displacement feedback control method is used to provide active stiffness for the structure and then change the flutter characteristics of the structure. The results show that active control can effectively improve the anti-flutter ability of the structure.