Abstract: Based on the micro-damage mechanical principle，a micro-damage mechanical model for the stability analysis of high ground stress area was established and used in the simulation analysis of the whole process of the wall rock failure.The equivalent models for the wall rock in the damage area before and after its damage were built by adopting the concept of equivalent model.The mechanical property curve obtained from the numerical mechanical experiment was used in the quantitative study of the change regularity of the main mechanical parameters（strength，deformation modulus）of the rock mass in the wall rock excavation fracture zone along with the construction process.The change values of the main mechanical parameters of the rock mass thus obtained has provided a reliable basis for the rock mass stability analysis and the structural design and further defined the partitioning standard for the disturbed areas of the wall rock by the excavation.

Key words: Rock mass in damaged area, Mechanical property, Micro-damage mechanics, Equivalent model