Abstract: The analysis on deformation mechanism of soils is very complicated in the DTH percussion-compact drilling process,which is not only involved in the problem of material nonlinear and geometrical nonlinear,but also involved in the problem of contact friction.Therefore,it is the high nonlinear problem.The finite element model is preliminarily established by ANSYS in the process of DTH percussion-compact drilling in soil,the stress and strain displacement status of the soil around the drilling tool was simulated and analyzed.The results show that the plastic flow is generated following the increasing pressure in the soils under bit,sharp deformation and failure are also generated.The soils around drilling tool are rebuilt and disturbed.Therefore,the engineering properties of soil vary greatly and the soils around hole wall are relatively compacted and stable.