Abstract:Based on rough set theory and the index set, representation system of influencing factors of destroyed floor depth has been set up, and rule extraction principle has been put forward. Through data processing of rough set decision rule, factors controlling order of destroyed floor depth is mining depth, coal seam inclination angle, workface inclined length, mining thickness, coal floor antidestructive capacity; faults or broken zones. Because parameters of coal floor antidestructive capacity and faults or broken zones is difficult to determine, by using other four influencing factors, destroyed floor depths based on BP networks have been built. The destroyed floor depths of No.9101 workface and No.9507 workface in Feicheng coal field have been predicated according to the established network model. By comparing the results of neural network model and the results of empirical formula provided by national regulations with the actual measurement results, the results obtained by neural network model are closer to reality than the results of empirical formula calculation.