Floor impact is one of the manifestations of rockburst disasters. Defining the inherent impact properties of floor can better evaluate the risk of floor impact and guide the prevention and control of floor rockburst disasters. On the basis of referring to the classification of roof rock stratum impact propensity and index determination method, by simplifying the simply supported beam stress model, with the aid of the method of equal small deformation displacement and equal rock beam length, the stress action of floor rock stratum is equivalent to a uniform load. Based on the thin plate theory, the expression of critical stress was derived to determine the location of the floor main rock stratum and the number of layers of bending deformation rock stratum, and calculate the bending energy index of floor rock stratum. Based on this, the floor rock burst tendency was judged, the classification and identification process of floor rock burst tendency were established. Taking Yuejin Coal Mine in Yima Mining Area as an example, the method was verified. The results showed that the impact tendency of 2-1 coal floor strata in Yuejin Coal Mine changed from weak to strong, which was more in line with the actual situation on the spot, and proved the rationality and feasibility of the method.