The tip-over stability of cherry pickers is degraded by the Cherry pickers’ payload oscillations. As a first step, a static model was given to provide the basic insights into the whole system. After a simple mode of cherry pickers with flexible arms being shown, the complete multi-body dynamic mode was established based on AUTOLEV. The response curves of the arms’ angles and payload to the step signals were simulated. From the simulations, it can be seen that the performance of the base and the arms are all can lead to the significant payload oscillations, which will thereby result the unsafety of the cherry picker. The full analysis of the payload vibration is the basis for repressing the system vibration.