Abstract: Severe thermal stress will be generated on the window structure when the vehicle flies fast in the atmosphere because of heated air. The window structure may possibly be damaged or the optical error may be increased by thermal stress, accordingly. It is necessary to analyze thermal stress field of the window structure. Thermal stress of a glass window in aerodynamic thermal environment was analyzed, relative wind tunnel experiment was made to measure its thermal stress. A special brace was designed taking the character of the glass window into consideration. Thermal stress experiment for the glass window model was done in a high-frequency plasma wind tunnel. During the experiment, high temperature strain was measured using the resistance strain gages. The ways and characters of installing strain gages on glass window model were introduced. According to the feature of rapidly increasing temperature during the experiment, transient thermal output and steady thermal output of the strain gages was calibrated and compared. The stress and strain of glass window in aerodynamic thermal environment were obtained, the highest temperature reached up to 300℃. The thermal stress analysis of the window model was investigated numerically using a finite element software. The error between the measured values and the computed values of the window model's thermal stress was about fifteen percent, and the experimental results were identified. The experiment shown that the glass window model was affected by compressed stress. Stress state of the glass window model under the experimental condition is normal and the glass window won't be damaged by thermal stress.