Abstract: In response to the issue of insufficient tensile strength of the drill pipe as used for deep earth oil-gas exploitation in the country，relevant critical technical bottlenecks have been overcome，including upsetting of the extra heavy pipe body，heat treatment，and friction welding，etc.，resulting in the R & D of the Φ168.3 mm drill pipe as used for the extra-deep well. The result shows that the said drill pipe possesses such properties as maximum suspended load up to 942 t，and weld maximum suspended load up to 1 041 t；the pipe body transitional section is long over 140 mm，which properly distributes the pipe-end stress，and enhances the efficiency and safety of drilling the said well. The R & D has promoted the successful completion of the 10 910 m drilling operation of the Well Shenditake 1，supporting the development of the domestic deep earth engineering.