In this paper, the multidisciplinary coupled dynamics simulation method and reliability modeling method are studied for the problems of low accuracy, stuck and strength degradation of aero engines. Based on the ADAMS software platform, the parametric modelling is proposed for aero-engine guide vane adjustment mechanism of variable geometry turbine, and the parametric model is simulated. The effects of dimensional uncertainty, component deformation, load uncertainty, strength uncertainty and strength degradation on the reliability of the mechanism are considered. Through simulation analysis, the key factors affecting the reliability of the mechanism can be identified and guidance can be provided for the establishment of the reliability model. Finally, the reliability of the mechanism regarding motion accuracy failure, stuck failure and strength failure was calculated by Monte Carlo method.