Abstract—It’s intrinsic properties for geotechnical material to crush after loading or other mechanical impact. Therefore, one of the primary questions need to be solved is to define the degree to which the particles of an element of soil are crushed or broken during loading. Considering the fact that with continued particle crushing the proportion of smaller diameter particles will increase and there is a tendency for the grading to become increasingly “self-similar” or “fractal”. Thus, based on the lope and correlation coefficient of fitting line, the article proposes a concise method to describe the revolution characters of particle crushing state. Combining with two sets direct shear tests of specific grading, the relationship between the parameters of particle crushing state and strength index φ is discussed. It’s confirmed that the parameters of particle crushing state have clear physical meaning and wide applicability.