In order to clarify the longitudinal influence relationship and the hierarchical structure between the causes of traffic tunnel construction accidents, based on the perspective of the whole process of the accident and the construction of the accident cause system with text mining technology ,this paper used the decision-making trial and evaluation laboratory (DEMATEL) and the interpretative structural modeling method (ISM) to judge the importance of each cause, established a multi-level hierarchical structure model of the accident cause, constructed an accident-causal impact chain for causes at key positions, deeply analyzed the longitudinal impact relationship between each cause, and took the WLM tunnel as an example to verify its validity. The research results show that There are 20 causes of traffic tunnel construction accidents, which have obvious hierarchical structure. Personnel, management and environmental factors have a direct impact on technical factors, mechanical equipment and material factors. Among them, safety awareness and literacy, safety supervision, construction plans and various environmental factors occupy an important position in the accident cause system, and effective management and control of them is the embodiment of good safety management. This research can provide reference and basis for the safety management of traffic tunnel construction.