Abstract: Relevant factors as affecting the collapse strength of the casing are verified with the finite element analysis(FEA)software, focusing on such factors as the geometric dimensions of the pipe body of the Φ139.70 mm×7.72 mm P110 casing, including O.D., wall thickness, and ovality, and the mechanical properties of the pipe body;Analytical comparisons are conducted with FEA simulation test result and the full scale collapse test result, the 2-D and 3-D simulation test results, and the influence on simulation resuit by the loading of the internal pressure with the normal atmosphere.As a result of the analysis, it is regarded that both the ovality and wall thickness of the casing pipe body produce significant influences on the said collapse strength, which needs to be properly controlled in actual operation.