Abstract: Analysis on the dynamic characters of case pipe is an important process in the design of casing drilling.With the assistance of ANSYS software,the finite element modeling is established to solve the dynamics of the assemblage of case pipes at different drilling pressures and different rotary speeds.The variance patterns of stress and strain of case pipe and the contact stress indifferent drilling parameters are obtained,which are the theoretical basis for optimizing the drilling parameters during the operation of case pipe drilling.