Abstract: To study the research progress of tunnel fire comprehensively, visual analysis is conducted on literature temporal distribution, keyword clustering, research institutions and scholars, research hotspots, and frontier trend of papers related to tunnel fire from 2000 to 2022 based on CNKI and core collection database of Web of Science, and using CiteSpace analytic tool. Findings are as follows: (1) The overall volume of publications in the field of tunnel fire has shown an increasing trend and grows rapidly after 2014. Chinese scholars take the leading position in this field and receive widespread influence across the world. (2) The main research topics include numerical simulation, ventilation and smoke extraction, smoke temperature, and emergency evacuation. Prominent research institutions such as University of Science and Technology of China, Central South University, and RISE Research Institutes of Sweden and their scholars are main research forces. However, the collaboration and communication among research teams is relatively small. (3) With the increasing complexity of tunnel types, the frontier hotspots gradually focus on tunnel slopes, ambient pressure, and bifurcated tunnels. (4) For future research, with the help of artificial intelligence, big data, and other emerging technologies, interdisciplinary integration and academic cooperation can be further strengthened. Laws and regulations in tunnel fire should be improved and revised to enhance international status.

Key words: tunnel fire, smoke, CiteSpace, bibliometrics, knowledge map