The spindle is the core component of the integrated transmission device,and its reliability directly affects the normal operation of the integrated transmission device.Aiming at the fatigue failure mode of the integrated transmission spindle,the reliability analysis was carried out considering the parameter uncertainty based on the finite element simulation.A model of the fatigue fracture spindle was established for transient dynamic simulation,and the maximum shear stress under load condition was obtained.On this basis,the influence of the parameters dispersion on the strength and stress of the spindle was analyzed,and the reliability was calculated by Monte Carlo sampling method based on the generalized stress-strength interference theory.In practice,unexpected broken shaft failures occur many times under special tasks,and the actual service life of the spindle is far lower than the design life.Taking this special task as an example,the reliability analysis of the spindle was carried out.The results show that the reliability analysis method considering uncertainty is feasible for fatigue broken shaft failure.The fatigue life of spindle under special working conditions is obtained through case analysis.