Abstract: Analysis for Dynamics Simulation of RigidFlexible Coupling Gear To obtain dynamic characteristic of gear train system more accurately in MSC.ADAMS, transmission shafts were dispersed; then numerical simulation was used to gain interior dynamic excitation of gearing and the torsion vibration model of gear pair was transmitted to an equivalent model to calculate; the dynamic characteristic of rolling bearing working with sufficient lubrication was simulated. The model which can take the consideration of gearing timevariable traits, lateraltorsional coupling of train shafts and bearing flexibility was eventually constructed. The conclusion demonstrates that the simulation results based upon different conditions differ from each other and flexible bearing accords with the fact more precisely.