Abstract: The torsional strength of the drill stem tool joint is generally lower than that of the pipe body thereof.To meet the need in this regard the non-API hi-torsional strength double shoulder connector is selected.Then two large-scale FE analyzing softwares named I-DEAS and MARC are used at the SGI INDIG 02 IMPACTR 10000 working station for relevant computerized simulation to analyze the stress distribution on the double shoulder tooth surface and in the shoulder area of the S-135drill stem connector.The result of the calculation is compared with the API standard connector,which has brought about such a conclusion that the torsional strength of the said double shoulder connector is as high as 1.5 times the API standard connector.