Abstract: In order to study the effect of suture on the tensile properties of thermal protection structures, a suture-stitched reinforced sandwich structure (ceramic-aerogel-ceramic) model was proposed. With the help of finite element software programming language modeling, the internal stress-strain field of the stitched reinforced sandwich structure was determined by multi-step stepwise and accurate analysis. Firstly, the finite element analysis of the stent and the experimental piece without suture was carried out; then the detailed structure such as suture was considered; finally, the substructure was taken for detailed analysis. The stress variation trend of the sandwich structure finite element model was compared with the test results of the test piece. The validity of the finite element model was verified and the variation law of the finite element solution was given. The stress-strain curves obtained by the stitching reinforced sandwich structure and the unstitched sandwich structure were compared. The results show that when the structural bottom plate is uniaxially stretched and the suture is prestressed, the stress peak of the suture reinforced sandwich structure along the length direction (x direction) can be effectively reduced (the maximum stress on path 1 is reduced by 4.6%); the stress along the z direction (path 3 is reduced by 30% on average) can be drastically reduced.