To achieve lightweight of the compression-shear test machine frame,the force condition of the compression-shear test machine frame under limited working conditions was analyzed,and the static analysis of the compression-shear test machine frame was performed by using Abaqus.Variable density-based topology optimization method was applied to optimize the topology of the compression-shear test machine frame,and the model was re-established accordingly.Finally,the static characteristics,the modal characteristics,and the dynamic characteristics after sudden unloading of the original and optimized frame were compared and analyzed.After optimized,the weight of the frame is decreased by 14.5%; the maximum static stress and the maximum displacement are less than the material yield strength and the maximum allowable displacement,meeting the requirements of static strength and stiffness; the natural frequency of each mode is much greater than the working frequency,meeting the requirements of dynamic stiffness; the maximum dynamic stress of the beam,column,and base of the frame after sudden unloading are all less than the material yield strength,meeting the requirements of dynamic strength.