As essential elements of the graphite reflector in thorium-based molten salt reactor, dowel–brick structures are used to withstand complex working loads in the reactor core and their failure may lead to serious damage of the graphite reactor core. It is crucial to investigate the stress behavior of dowel–brick structures for safe operation of the graphite reactor. In this study, three groups of finite ele-ment analyses and a strain test were carried out to inves-tigate how the geometric parameters of the dowels affect the stress behavior of the dowel–brick structure. The numerical results indicate that the stress behavior of a dowel–brick structure is significantly affected by the diameter, length, and aspect ratio of the dowels. The maximum stress in the lower and upper bricks decreases with an increase in the dowel length. The location of maximum stress on both lower and upper bricks shifts from the root of the socket to the edge of that socket beside the contact region, as the length of the dowel increases. The shift of the maximum stress location occurs earlier for the upper bricks than for the lower bricks. The results of strain tests show good agreement with those of numerical analyses.