Dynamics characteristics and relative tests on a type of rotary seedling pick-up mechanism of planetary gear train with combined gear transmission of incomplete eccentric circle gear and non-circular gears were studied. Based on the force analysis of each moving component in the seedling pick-up mechanism with the dynamic static analysis method and dynamics equations sequence-solution method, the dynamics mathematical model of the mechanism was built, and the dynamics analysis software was developed to solve the model to obtain the force variation law of different positions, including the chain, rotary centers and mesh points of gears and bearing of the mechanism. The virtual prototype of the mechanism was set up and its physical prototype was manufactured to conduct dynamics simulation analysis and bench tests on the mechanism, respectively. The relationship between the bearing reaction force and the rotation angle of the planetary carrier was obtained when the mechanism was rotated at 60r/min.The variation law of bearing reaction force under theoretical analysis, dynamics simulation and bench test of the seedling pick-up mechanism were basically consistent, which verified reliability of the dynamics model and correctness of dynamics analysis of the seedling pick-up mechanism. By contrast to the original seedling pick-up mechanism, it can be obtained that the maximum amplitude and variance of bearing reaction force in the y direction of the seedling pick-up mechanism were reduced from 155N and 1171N2 to 77N and 553N2, which were decreased by 50.3% and 52.7%, respectively, indicating that the mechanism had better dynamics performance than the original mechanism.