Abstract: Aiming at the problem of the fatigue fracture of wind turbine bolts due to preload relaxation,a single-section model of wind turbine tower ring flange connection is used to analyze the sensitivity of preload relaxation caused by friction and room temperature creep using the finite element method. The results show that the maximum thread stress decreases by 8.04% and the average stress increases by 16.4% when the friction coefficient is reduced,and the preload only decreases by 15.74% and 6.37% respectively when the material creep characteristics are low and the yield stress is high. Therefore,when the friction between the thread contact and the external contact surface is low,and the bolt material has low creep characteristics and high yield strength,the bolt has better creep resistance and is less prone to preload relaxation. At this time,the bolt connection state and preload distribution are better,the maximum stress of the thread is smaller,and the contact pressure and clamping force between the flanges are higher,which effectively reduces the preload relaxation.The research results provide a theoretical basis for solving the problem of preload relaxation of wind turbine bolts.