Abstract: In researching the fluid elastic characteristics of the rudder system, it is found that the results of rudder system flutter characteristics based on the binary linear flutter wing model are consistent compared with the literature simulation data. The rudder system flutter influence laws of such linear parameters as frequency ratio, gravity center and torsional rigidity are obtained by calculating using the aforementioned model. In addition, combined with the two degrees of freedom binary wing hydrodynamic calculation method for the arbitrary time domain, the rudder system nonlinear flutter phenomena is calculated, and the influence of nonlinear flutter caused by the transmission interval is analyzed. The research results provide a fundamental analysis method for the fluid elastic characteristics of rudder systems. The results can also support the anti-flutter design of rudder systems.