Abstract: Due to the immaturity of drilling and completion technology for large boreholes in compressed air energy storage wells, research on special tools such as injection-production packers and injection-production wellhead devices for casing completion is still in its infancy. Moreover, there are significant differences compared with conventional oil and gas well technology. Therefore, personalized design of drill bits and expanders, optimization of drilling parameters and drilling fluids, and other rapid drilling technologies of large boreholes were carried out. Mechanical analysis of the bottom hole assembly and stability control of drilling tools to prevent fatigue damage were conducted. Research on key technologies such as safe casing running, optimization of cementing process, and sealing of completion tubing and annular space was performed. The key technologies for drilling and completion of large boreholes in compressed air energy storage wells were developed and applied on-site. The on-site application results show that the selected drill bit and reamer have stable performance, and the selected bottom hole assembly can achieve safe and fast drilling. The completion string has excellent sealing performance and stability, meeting the requirements for repeated injection and production. The injection-production packers for casing completion and the injection-production wellhead devices developed have all passed the sealing test. The research results have provided technical support for the construction of the compressed air energy storage power station demonstration project.