Abstract: The forced vibration method is one of the main techniques for identifying bridge flutter derivatives. First, four forced vibration schemes are proposed and compared in terms of displacement control accuracy and implementation cost. A three-degree-of-freedom forced vibration test system suitable for large-load conditions is then developed. This system consists of a forced vibration device and a testing system, with a model length of no more than 2.1 meters, making it suitable for identifying flutter derivatives of conventional scaled bridge models and considering the effect of crosswinds. The accuracy of forced vibration displacement and the synchronization of force balance measurements with displacement are further verified. The method for eliminating inertial forces during balance force measurements is also discussed. Finally, a flat plate model is used as an example to identify flutter derivatives, and the results are compared with theoretical solutions. The results show that the maximum displacement error under large model mass is approximately 0.5%, and the maximum synchronization error between the main and auxiliary axes is about 0.6%. The identified flutter derivatives of the flat plate model agree well with the theoretical solution, demonstrating that the test system can effectively identify flutter derivatives.