Abstract: Four typical well barrier charts were used to illustrate the well barrier and the structure, function and acceptance criteria of its components based on Norway's standard NORSOK D-010 and PetroChina's wellbore integrity standard on three-high well. First, the functions, operation technical standards and requirements of the important components for well barrier in drilling operation were described, including drilling fluid column, drilling string, blowout preventer and wellhead assembly. There are four attached tables in the appendix. Second, the definition, structural characteristics and application methods of so called "shearable string" and "non-shearable string" were read from the point of domestic idioms. Third, the well control procedure and the key points of drilling operation under the conditions of well control were illustrated, and the requirements and standards related to wellbore integrity and well barrier in drilling operation were expounded. Finally, the risks of shallow gas layers and the corresponding operational measures, the well trajectory and the well spacing standard and measurement method were briefly introduced.