The logging harvester is made up of a walking mechanism, a mechanical arm, a felling head and a driving control system, which can do the works of felling, limbing, measuring and bucking. Because the ground surface of the forest land is very rough, the vibration should be studied when it is going in the forest land in order to prevent the harmful effects to the machine and driver. In this paper, the logging harvester is simplified as a vibration system of 5 degrees of freedom, then the vibration differential equation is established by the method of the second Lagrange dynamics equation, and in the circumstance of the Matlab\Simulink software, the simulated calculation is produced by the universal solver. The calculated result shows that the vibration performance of the logging harvester can meet with the demand of going in the forest land.