Particle crushing after impacted by loading or other mechanical factors is the intrinsic property of geotechnical material, so proposing the reasonable parameters to describe the crushing state is the primary step to study particle crushing. Considering the fact that the proportion of smaller diameter particles increases with the particle crushing and there is a tendency for the grading to become increasingly “self-similar” or “fractal”. This paper proposes a concise method to describe the particle crushing state based on the slope and correlation coefficient of fitting line. On this foundation, the concepts of crushing fractal index(CFI) and crushing fractal correlation index(CFCI) are defined and their development law are both elaborated. Compared with the experimental data, the indexes proposed in this paper are consistent with the data; and an obvious relationship between particle crushing state and the two indexes is existed. Therefore, the CFI and the CFCI can be used to reveal both the degree of particle crushing and the trend of particle crushing development, so as to provide a new approach to study grain breakage problems.