A rod fastening rotor used to be treat as a continuous integral rotor, so the model is not very precise. By considering the contact effect of discontinuous interfaces, a dynamic model of rod fastening rotor’s torsional vibration is put forward by using bond graph. The influencing factors of equivalent torsional stiffness have been analyzed. The theoretical results and the experimental results of an experimental rod fastening rotor’s torsional vibration have been contrasted. The natural frequency of rod fastening rotor and continuous integral rotor’s torsional vibration has been analyzed under different pretightening forces. The vibration mode of continuous integral rotor and rod fastening rotor whose pretightening force is 4000N have been contrasted. The contrast results show that the model of rod fastening rotor is not only more precise than continuous integral model, but also it represent the essential difference between rod fastening rotor and continuous integral rotor, it can settle the foundation of the further research on rod fastening rotor.