Bogie frame is one of the important parts of an urban subway vehicle, but it usually occurs to fatigue crack. Traditional dynamic characteristic analysis for bogie frame is generally based on multi-body dynamics simulation and finite element analysis, this method is suitable for the structural natural frequency away from the external loading frequency, consequently its result has certain limitations. In order to study dynamic response characteristics and fatigue strength of a bogie frame，a rigid-flexible coupled multibody dynamic model of the bogie frame is established based on the finite element analysis method and the rigid-flexible multi-body dynamics theory. The dynamic stress response of bogie frame is carried out based on rigid-flexible coupling multi-body dynamic model of the metro vehicle, from which vibration characteristics of this type of the bogie frame can be obtained. Then, failure mechanism of the bogie frame can be obtained based on fatigue analysis of local fatigue areas of the bogie frame. The stress time histories of its bogie frame necessary for fatigue analysis are calculated with the results of the multi-body dynamic simulation taken as the dynamic load by using the finite element analysis method. The fatigue life of the bogie frame is predicted by using the quasi-static stress superposition method. The calculation results show regions of the bogie frame with excessively large stress amplitude are concentrated on the motor hanger region, gear box hanger region and the connected region between the beam and side beams. The simulation result conforms to the location of actual fatigue bogie damage on this frame, thus verifying the correctness of the method on structure fatigue analysis based on the rigid-flexible coupled model. The shortest lifetime of the motor hanger obtained from the simulation is 1 530 000 km. The error of the result of simulation and the actual data is 10%, which illustrates high credibility and accuracy of the simulation.