Abstract: Techniques of Internet of Things (IoT) have great advantages for offshore well drilling/completion in harsh environments with high risks. During intelligentization of offshore oilfields, the offshore well drilling/completion based on the Internet of Things was preliminarily developed by constructing the IoT core architecture for offshore well drilling/completion, deploying edge IoT acquisition nerve terminals, and improving the industrial Internet. With the IoT techniques, rapid progress of offshore well drilling/completion has been made in multi-disciplinary fields, which realized the information digitalization mutual communication of the bottomhole and wellbore, the information digitalization fusion of formation data and the well trajectory, and oil well lifecycle safety digitalization. The goods-and-materials tracking technique ensures efficient regional resource sharing and also personnel safety. Applications of Internet of Things in offshore well drilling/completion represent bold innovation and breakthroughs of the conventional petroleum industry, which has gained preliminary achievements and highlights wide application prospect.