The thermal-acoustic vibration response characteristics of metallic thin-walled structures were investigated based on time-domain analysis method, and four kinds of stress life models were employed to predict the thermal-acoustic fatigue life of a clamped thin-walled aluminum beam. Time-domain response characteristics of a typical beam model under acoustic loading and thermal-acoustic combined loading were determined via numerical simulation. No snap-through response is presented under any single acoustic loading level. On the contrary, in the thermally post-buckled condition, increasing sound pressure level is previously shown to evolve the response from vibration around one of the positions, to intermittent snap-through and finally to persistent snap-through between the two equilibrium positions. On this basis, a cumulative damage model was employed using a rainflow cycle counting scheme and fatigue estimates were made for 2024-T3 aluminum using four fatigue models, namely Goodman, Morrow, Walker, and modified Walker. The results show that: thermal fundamental modal of the beam in thermal-acoustic fatigue problems is predominant; the snap-through motion between multiple post-buckled equilibrium positions introduces very high alternating stress which weakens the fatigue life expectancy of the beam; acoustic loading is a major factor which determines pre-buckled configuration life of the beam, while thermal loading is a major factor which determines post-buckled configuration life. Therefore, anti-fatigue design of the thin-walled structure under thermal-acoustic loading must study the impact of the combined effects of thermal acoustic loading.