The elastic-plastic constitutive relationship and the Drucker-prager yielding criterion are used to simulate the behaviour of non-linear geo- materials. Dynamic change laws of abutment pressure of S2S2 work face of xiaokang coal mine is simuluted by the ansys program. It is shown that the distribution of abument pressure can be divided into two zones, elastic region and plastic region. The front inside the 13m distance is plastic zone. The zone outside 13m distance is elstic zone. The affecting scope is 144m when the concentrated coefficient of abutment pressure is 5%. The affecting scope is 160m when the concentrated coefficient of abutment pressure is 3%. The simulation provides a reference bases for the application and promotion of thick seam mining technology.