Abstract: The identification of impact tendency of coal and roof has become a national standard. However, it is still an urgent problem to determine the criterion and method of floor impact tendency. After analyzing the structure of floor rock, load transfer path and failure mechanism, a method for calculating the impact tendency of the bottom plate based on the bending strain energy formula was proposed. Based on the conventional mechanical properties of the floor rock, the impact tendency and its correlation were discussed, and the decision index was given. Through the comparison and statistical analysis of Dafosi Coal Mine, Bailongshan Coal Mine and Huafeng Coal Mine, it showed that the method was feasible and reliable. The method and standard of the evaluation of impact tendency of floor rock strata was proposed.