Abstract: Edgewise compression experiments were conducted at different temperatures for the stitched aerogel-core sandwich composite, and the edgewise compression mechanical properties were investigated at RT, 300℃, 600℃ and 800℃, respectively. Micro-focus industrial computed tomography (Micro-CT) technology was adopted to scan the internal structure of the composite. And combined with FEM analysis method, edgewise compression failure mechanisms were discussed. The results reveal that in the case of edgewise compression, the composite has ultimate load. The local buckling of the panel, shear failure of the core and crush of the stitches are the main damage mechanisms of the specimens. With the increasing temperature, the edgewise compression modulus and the ultimate stress increase, and the fracture mode of the panel trends to be brittle. The compression modulus of 300℃, 600℃ and 800℃ is about 1.05 times, 1.57 times and 1.65 times that of room temperature, respectively, and the ultimate strength is 1.14 times, 1.46 times and 1.67 times that of room temperature, respectively. The comparison of finite element analysis results and the experimental results at room temperature shows that the failure mode of the stitched aerogel-core sandwich composite is reasonable.