Abstract: Set stratum-cement sheath-casing combined system as study target,based on elastic-plastic mechanical theory,set up nonlinear finite element mode,carry on research of the relation on the casing deformation,ground stress change and non-uniformity.Analyse the relation of external load and deformation of different specification casing under different condition,based on the finite element calculation,draw up the casing deformation scope map of different minimum horizontal major stress and maximum horizontal major stress,which could predict the casing shrinking deformation under the non-uniform ground stress directly,therefore provide reliable basis for applying reasonable and effective casing damage prevention measures at site and later completion implementation.