Abstract：The dynamic model of diesel generator sets with six degrees of freedom is established. The sixth-order vibration modes are analyzed and the modal coupling characteristics are researched. Simultaneously,the response of all degree of freedom of the diesel generator sets are obtained based on the new forecast-correction time domain integration method after calculating the excitation. And the vibration intensity of the diesel generator sets are calculated based on the frequency domain integration method for rotating mechanical vibration intensity.At last the suspension stiffness is optimized. The results show that the horizontal vibration becomes very intense because of the yaw, roll and shaking head modal coupling effect.The longitudinal vibration becomes negligible because of the lack of exciting in the longitudinal direction of the diesel generator sets,although the existing horizontal-moving and node coupling effect are coupled.The pitch mode can be highly decoupled, so it acts alone to make vertical vibration. The transverse vibration intensity decreases from 26.39 mm/s to 16.65 mm/s after the stiffness optimization of absorber. As a result,the vibration is brought under effective control.