To reduce the serious vibration and fruit dropping that may occur in highspeed robotic harvesting of fruit clusters, a simulation model of fruit cluster vibration is necessary to vibration law discovery, influencing factor analysis and optimal control study. To achieve all of the above objectives, the simulation model must take into account of the individual difference of component properties and embody the complex multilevel stem structure, multiple fruits distribution and multiplex excitation transmission. Therefore, a flexible rodhingerigid rodmass composite model was first put forward based on the structure of stemfruit system of grape cluster, and viscoelastic property of hinges and bending property of main spikestalk were determined by large sample tests. Then, simulation model of grape fruit cluster was constructed by reconstitution of the solid stem system with 3D laser scan, replacement of main spikestalk with flexible rod, random addition of fruits and definition of different components according to their normal distribution from the above test results. The accuracy of the simulation model was verified by experiments, and error of the mean value and standard deviation of fruit relative swinging angle under different excitation methods are within 2% and 6.6%, respectively. Finally, the effects of various excitation methods and harvesting stages on cluster vibration were analyzed with this model. To conclude, the successful establishment of this simulation model of grape fruit cluster provides an excellent analytical tool for robotic lowvibration and antifall harvesting of various fruit clusters.