The shear tests of concrete under different loading rates and normal pressures are carried out using a dynamic and static three axis apparatus. Based on the improved Najar energy method, a new calculation method of damage variables is proposed to analyze the influence of normal pressure and loading rate on the damage evolution of concrete under compression shear stress. The compression shear damage model is constructed by combining the ascending section of Weibull model and the decline section of Zhenhai pass model. The results show that the new method of calculating damage variables agrees well with the actual load condition of concrete. The concrete compressive shear stress state under damage evolution can be divided into three stages: the elastic stage; the damage acceleration stage; the damage convergence stage. Normal pressure on the damage evolution of concrete play a significant role. The increase of normal pressure slows down the development of concrete damage, and the development of concrete damage has a trend of lagging behind the increase of loading rate. The constructed shear load deformation full curve damage model agrees well with the experimental data.