The solid propellant is a particle-reinforced material with significant tension-compression asymmetry. Based on the constant-speed tensile test, constant-speed compression test, and cross-sectional SEM scanning test, this study investigated the differences in the mechanical properties of the HTPB propellant under tensile and compressive loading and the underlying mechanisms. The results show that the tensile strength of HTPB propellant is much smaller than compressive strength. According to the SEM test results of the failure surface, the tensile mechanical properties of the propellant are mai...