Abstract: Based on the deficiencies in selection of conventional mining methods，a new method of exploring the gentle dip thin ore body with the hydraulic pressure support long wall method was put forward，through integrating the rough set theory with the fuzzy set theory in mining method optimization.With the comprehensive analysis of mining safety，economic，technical index and friendly environment factors，11 kinds of influence factors are taken as condition attributes and the results of mining optimization and evaluation are as decision attributes to build the mining method optimization evaluation index system，the membership degree matrix and weight coefficient matrix on the quantitative analysis for the proposed mining methods；The knowledge dependency and attribute importance of theory evaluation method is applied to transform the weight coefficient of fuzzy mathematics into rough set attribute importance evaluation.Discriminated rule is extracted from the reduction results to propose the calculation method of weight coefficient and determine the optimal scheme for hydraulic support long wall caving method.The results show that mining method selected by rough fuzzy set theory are adaptable，with features of safety，high efficiency and low consumption.It makes the selection of mining method more scientific and objective，and has a higher theoretical and engineering practical value.

Key words: Rough fuzzy set theory, System of appraisal factors, Optimal mining method, Optimization evaluation