Abstract: Due to the harsh operation conditions of the drill collar in oil exploration,stringent criteria is put forward for performance thereof. The conventional manufacturing process for the drill collar features such disadvantages as rather long processing cycle and low cost efficiency. Elaborated in the article are the manufacture of seamless steel pipes for drill collar stock purpose with Assel pipe mill,covering such aspects as the process R & D,the deformation distribution during the rolling process of the drill collar-purposed heavy-wall pipe and optimization of the process parameters which crashes the hard nuts of process control for the purpose of rolling consistency.