The calculating method of RMR value is introduced.Combining with Hoek-Brown strength failure criterion and the results of related study,a computer program was compiled to realize the fast translation from the results of engineering geological survey to the mechanical parameters of rock mass.The method was applied to determine the mechanical parameters of f jointed rock mass in the horizontal ore layer at the No.2 mining area of Jinchuan,and the results showed that this method can precisely reflect the mechanical behavior of the jointed rock mass,and is effective and feasible,so is of great practical value.