Abstract: The failure tree analysis method was used to analyse the failure parameters for the gear fracture failure problem occurring in the gear-shaft interference coupling. A fault tree analysis model was established to identify the various potential factors of failure, and the importance of each factor was analysed to find the five main influencing factors of interference, friction factor, press-fit speed, assembly deviation and shape error. A transient dynamic analysis of the gear-shaft interference coupling system was carried out using the finite element method to study the stress influence law of the five main factors. The results show that the contact stress between gear and shaft increases with the increase of interference and friction factor, but does not affect the trend of stress distribution; the increase of assembly deviation and shape error will increase the contact stress, and the press fitting speed has almost no effect on the contact stress.