Abstract: The paper introduced the method of obtaining Hoek Brown model parameters and other physical parameters of rock mass by RocDate software according to the rock uniaxial compressive strength，the geological strength index，the rock material parameters，the excavation impact factor，based on the field investigation combining with laboratory tests.Then，the transition and cohesion between the indoor rock mechanics experimental parameters and the field actual rock mass parameters can be realized.By establishing the numerical analysis model，and with the use of geotechnical engineering software FLAC3D，the stability of the jointed rock slope after excavation in southwest section of Songshunan's mining area is analyzed according to the basic parameters of Hoek-Brown-constitutive model acquired.The results show that:①The slope in southwest section is in stable after excavation without large-scale collapse and slippage problem;②Shear stress concentration phenomenon appears on the steps at the bottom of the slope;③small amounts of communicating plastic zone appears in the slope excavation steps，and instability exists in some local slopes.So these zones should be monitored and supported.

Key words: RocDate software, Hoek-Brown model, Geological strength index, Stability analysis