Abstract: The compression tests of 300 mm concrete cubic specimen under different lateral pressures and different loading rates are carried out by using a dynamic and static triaxial test machine, and the mechanical parameters of the test data are analyzed. On this basis, the K-G failure criterion considering the dynamic loading rate is established and its applicability is verified. The results of validation analysis show that the lower the strain rate is, the more obvious the effect of lateral pressure on the peak stress of concrete is; the peak strain of concrete decreases first and then increases with the increase of the strain rate; the peak strain of concrete increases with the increase of the lateral pressure, and the effect of the lateral pressure on the peak strain is more significant when the strain rate is low; the elastic modulus of concrete increases first and then decreases with the increase of strain rate; and the influences of the lateral pressure on the elastic modulus of concrete is not significant. The improved K-G criterion is more effective in describing the dynamic biaxial compression model, and the model can also be used to verify and analyze the uniaxial and biaxial stress states of 100 mm and 300 mm concrete cubic specimens.