Multi-row planetary gears are used in the gearshift mechanism of high-speed tracked vehicle to realize the shift function. Due to the coupling between different planetary gears， the mapping relationship between internal excitation and vibration characteristics is still unclear. According to the design scheme and shift logic of the planetary transmission mechanism， based on the second Lagrangian equation， the differential equation of mass coupling vibration of planetary gearshift mechanism is derived， and a general multi-row coupled planetary gearshift dynamic model is established. The results show that the time domain simulation value of the input component acceleration is basically consistent with the experimental test value， and the frequency domain characteristics of the acceleration of the planetary transmission mechanism are also basically consistent with the experimental test results. The simulation and experimental research results can provide the theoretical basis for the dynamic optimization design of the planetary transmission.