Abstract: The BQ method are widely applied for stability classification of surrounding rock mass in rock engineering field,three indexes included initial geostress,structural plane and groundwater were used to revise the BQ value in the course of classification,however,there two indexes,modified coefficient of groundwater and modified coefficient of structural plane,are differences exist in selection.The score calculation method revised with weighted average is proposed,which could provide basic data for economic and rational tunnel support by stability classification with modifiedBQ'value.The results were agree with the actual situation in the mine,which proved the method was accurate,and could improve the accuracy of BQ method for stability classification of surrounding rock.