The large special environmental equipment KM6 is subjected to repetitive stress. In order to assure the safely of space laboratories, two kinds types of thermal shroud structures with T and L shape were chosen and the stress analysis was carried out by use of PATRAN & NASTRAN software under stress and temperature spectrums. The stress of critical part was determined. After that, the stress of the same parts was also obtained from experiments, and the results obtained by theoretical calculations and experiments were compared. The results obtained by the finite element method are approximately accordant to that obtained by experiment, and thus the work stress considering the effect of temperature can be determined by numerical method and then the safety of the thermal shroud structures can be predicted accordingly.