Abstract: Driven by the technological impetus of the Fourth Industrial Revolution, the oil and gas drilling industry is rapidly advancing towards informatization, digitization, and intelligentization, with drilling digital twin technology emerging as a frontier and hotspot in the field. Drilling digital twin technology aims to map real drilling operations into virtual space and establish integrated, multi-disciplinary, multi-physical, and multi-scale virtual simulation models throughout the entire lifecycle of drilling. This enables functions such as pre-drilling rehearsal, in-drilling optimization, and post-drilling analysis, ensuring safe, efficient, and cost-effective drilling while enhancing the drilling efficiency of complex oil and gas formation. The current application status of digital twin technology in drilling engineering was introduced, and drilling digital twins were categorized into rig digital twins and wellbore digital twins. A five-dimensional system architecture for drilling digital twins was proposed. Furthermore, future development trends in drilling digital twins were analyzed, including real-time and efficient transmission of drilling data, refinement and quantification of geological models, multi-domain integrated modeling and simulation, dynamic adaptive updating of simulation models, the integration of mechanistic and data-driven modeling, safe and efficient human-machine interaction, and cloud-edge collaborative software system architecture. Relevant suggestions for the development of drilling digital twin technology in China were also proposed. The research findings could serve as a reference for establishing a drilling digital twin technology system and provide guidance for promoting intelligent innovation in the drilling industry.