A theoretical model of stiffened plate with multiple dynamic vibration absorbers under different boundary constraints is proposed in the current research. Compared with FEM, the solution efficiency of equivalent mass using model proposed in the current paper is improved by 90%. In addition, different boundary conditions and the connection relationship between stiffened plate and dynamic vibration absorbers can be easily implemented through virtual boundary spring stiffness and the introduction of auxiliary sine functions in the displacement function. The reliability of current method is confirmed by comparing with FEM, related literatures, and experiment. Based on theoretical model presented in the current research, the vibration control of stiffened plate under various edge constraints is discussed in detail. The theoretical model presented in the current research may be useful for engineering designers in the process of multi-line spectrum vibration control of stiffened plate.