Diesel generator system is a complex elastic support system which transfers the energy of diesel engine to generator. Vibration brings great harm to the reliability, safety and mute of the system. By constructing the equivalent fluid mechanics model of the inertia ring of the silicone oil damper in the shell, the mechanical characteristics and vibration damping mechanism of the silicone oil damper are studied. According to the established torsional vibration mathematical model of diesel generator system, the inertia matrix, stiffness matrix, damping matrix and excitation moment vector of torsional vibration are established by programming in MATLAB software. The system matrix method is used to solve and analyze the natural frequency and response vibration characteristics of diesel generator shafting. In order to verify the correctness of the vibration calculation results of the diesel generator system, the vibration test of the generator system is carried out by using photoelectric code and shafting vibration tester with independent intellectual property rights. It has a certain theoretical significance to reduce the vibration of diesel generator system and improve the safety of diesel generator system.