Abstract: The reasonable selection of rock mass mechanical parameters is the core issue in the sta‐ bility analysis of open-pit mine slopes. Taking an open-pit mine as the object，aiming at the problem that the traditional parameter value selection method is difficult to reflect the nonlinear strength characteristics of the rock mass，the rock mass parameter reduction method based on the generalized Hoek-Brown criteri‐ on is selected. Through the reduction of indoor rock mechanics test data，the complete rock mechanics pa‐ rameters are obtained. Combining geological strength indicators and blasting disturbance factors，a parame‐ ter reduction model considering the heterogeneity of rock mass and the nonlinearity of strength was con‐ structed. On this basis，the applicability of four types of deformation modulus calculation methods，namely the complete Hoek-Diederichs，the modified Hoek-Diederichs，the early Hoek and the simplified Hoek�Diederichs formulas，was systematically compared and analyzed. Research shows that the generalized Hoek-Brown criterion couples blasting disturbances with the structural characteristics of rock mass into the parameter reduction process，which can effectively reflect the heterogeneity and strength nonlinear charac‐teristics of hard rock mass，and significantly improve the engineering applicability of the parameters of hard rock mass. In the calculation of deformation modulus，the complete Hoek-Diederichs formula has the best calculation accuracy and is suitable for quantitative analysis of slope stability. The modified Hoek�Diederichs formula can be used as an alternative solution under the condition of missing parameters. The results provide methodological support for the selection of mechanical parameters of high-intensity dis‐ turbed hard rock slopes. The simplified Hoek-Diederichs formula is only applicable to rapid trend estima‐ tion. The research provides a theoretical basis and technical support for the selection of mechanical param‐ eters of high-intensity disturbed hard rock slopes，and has important reference value for similar mining projects.

Key words: generalized Hoek-Brown criterion, strength reduction, deformation modulus, rock mass mechanics parameters