Abstract: The oil and gas drilling industry is now facing lots of new technical challenges, and thus the screening of core drilling technologies is vital for making a drilling technology development plan scientifically. Based on the development strategy aims of the on-shore petroleum industry, this paper presents a set of suitable evaluation index system for evaluating the core drilling technologies qualitatively and quantitatively. The basic principle of Delphi Technique was applied and the core drilling technologies for the future ten year were screened out based on two rounds of experts questionnaire investigations. This method is more scientific and reasonable as it changed the past practice of screening solely based on qualitatively analysis. These technologies were integrated and finally five items of core technologies were screened out as RD focuses, and they were demonstrated briefly.