This article systematically summarises the digital twin technology in the existing scientific field using the bibliometric method, puts forward the critical areas and research directions at different stages of the life cycle of the digital twin research topic. Using R-Studio ‘Biblioshiny’ to measure scientifically, we visually analyze 514 articles related to digital twin in the Web of Science's core set from 2014 to 2021 (including SCI-Expanded and SSCI database). Firstly, we analyzed the core journals, articles, authors, institutions, relevant countries to determine the vital influence of digital twin-related literature. Secondly, we use theme maps to draw the research topics of digital twin-related literature as icons on the conceptual structure and offer four cluster parts (Motor themes, highly developed and isolated themes, Emerging themes, and Basic themes). Finally, we concluded by summarising the limitations of our study and subsequently highlighted future research directions. The study shows that monitoring, maintenance, and computer vision are research topics with good development momentum. Disturbance observer, reinforcement learning, and friction are relatively small research topics with a good development foundation, and scheduling, process modelling, and deep reinforcement learning are emerging research directions.

Information technology-acceptance research has always been a research hotspot. In 2003, Venkatesh established the unified theory of acceptance and use of technology (UTAUT), which pushed information technology-acceptance research to a new climax. This study uses bibliometrics, Bibliometrix, and CiteSpace software to conduct data mining and quantitative analysis on 1694 research papers in the UTAUT in the Web of Science core collection database from 2003 to 2021 (the data update time is 13 August 2021). Combined with a visual bibliometric analysis, this paper makes an in-depth discussion on the UTAUT model from the aspects of research trends, research fields, main research journals, authors/institutions, national or regional cooperation networks, etc. This study comprehensively and systematically shows the evolution track and characteristics of the UTAUT. On this basis, the future development trend of the UTAUT is put forward.