When testing impact dynamics of concrete, usually a variety of kinetic effects can be seen, such as the axial and lateral inertial confinement effects, the effects of stress wave propagation and the final friction effects, etc. Some of these are the material is nature itself such as the size effect, some are experimental errors, etc., but all the dynamic effects, may enter the final test results so that unnecessary errors or even wrong values may be brought into experiments. Due to the mechanism of friction effect, we have designed three different sizes of specimen for SHPB test. The quantitative values of the friction effect are obtained. The DIF is corrected, which is the basis for concrete impact engineering design.