In order to study the influence of the complex environment on the construction of urban underground space, an underground "日"-shaped urban traffic link tunnel in a city under construction is used as the research object. The risk factors of the project were analyzed qualitatively and quantitatively based on the fuzzy analytic hierarchy process combined with experts experience and statistical analysis. Urban traffic link tunnel construction risks were divided into four categories: geological environment risk, building environment risk, architectural design risk, and construction risk, and each risk is subdivided into two levels of index factors. Studies shows that there are high risks in the construction of this project. According to the results of the weight calculation, it is necessary to pay attention to the building design and construction risks caused by the complex construction environment of the project, including adjacent buildings, underground pipe networks, pipeline distribution during the construction process. The risk indicators in the two indicator layers are divided into three categories: primary, medium, and secondary influencing factors according to their weights, and corresponding risk prevention and control countermeasures are given. The research results of this paper can provide theoretical guidance for the risk control and management of urban traffic link tunnel construction in the future.