Abstract: To investigate the peeling mechanism of surface oxide films on power station boiler tubes, this study establishes a computational model for temperature and stress field distribution using the ANSYS fluid-solid coupling method. Taking T91 as the research object, the temperature and stress responses under various operating conditions were analyzed. First, the steady-state temperature and stress field distributions in T91 under 100% load were calculated. Subsequently, the analysis focused on the dynamic peak shaving process, simulating the evolution characteristics of the transient temperature and stress fields during a linear 90 ℃ temperature drop within 60 seconds. Finally, the dynamic responses during stepwise and curvilinear steam temperature drops in 60 seconds were compared. The results indicate that under steady-state conditions, the radial stress in the oxide film is the largest, followed by circumferential stress, with axial stress being the smallest. During the dynamic peak shaving process, a rapid drop in steam temperature significantly exacerbates stress fluctuations in the oxide film. In linear cooling mode, the stress peak occurs at the end of the cooling process, and the peak stress decreases over time. Stepwise cooling effectively suppresses stress fluctuation amplitude through segmented temperature control, while curvilinear cooling gradually reduces the inlet steam cooling rate via functional control. Both alternative methods yield smaller stress amplitudes than linear cooling, significantly reducing the risk of oxide film peeling.