In order to reduce the construction safety risk of tunnels in Yunnan Central Water Diversion Project and prevent the occurrence of construction accidents, it is necessary to predict the risk factors in advance. Considering the construction risk-inducing environment and hydrological, climatic and geological factors, we selected 8 primary indices and 19 secondary indices to build a safety risk evaluation index system for the construction of hydraulic tunnels, taking the specifications and engineering practice into account. The improved G2 and anti-entropy weight (AEW) method were introduced to calculate the subjective and objective weights of the indices, then the uncertainty measurement theory (UMT) and obstacle factor diagnosis were applied to establish the G2-AEW-UMT hydraulic tunnel construction safety risk evaluation model. The model validation was carried out on the simulation of the No. 7 tunnel of a project, and the results showed that the obstacle degree of climatic conditions in the slanting section, inlet section and outlet section of the tunnel scores the highest, which are 27.79%, 32.97% and 29.75%, respectively; that of geological conditions in the upstream section is the highest, which is 28.93%; and that of hydrological conditions in the downstream section scores the highest, which is 22.96%. According to the comprehensive diagnosis, the main obstacle factors affecting the construction safety of No.7 tunnel are climatic, hydrological and geological conditions, the mean value of the obstacle degree is 49.55% and the risk range degree is 62.5%, so the construction safety risk level of this hydraulic tunnel is evaluated as Ⅱ, which is categorized as the medium risk. Compared with the previous research, the fuzzy comprehensive evaluation results are consistent with the engineering practice, therefore, the proposed model is feasible. The combined model of unconfirmed measurement theory and obstacle factor diagnosis is applicable to the hydraulic tunnel construction safety risk evaluation with high feasibility and calculation accuracy, which can provide a new approach for the safety risk evaluation and diagnosis of the hydraulic tunnel construction in the Yunnan Central Water Diversion Project.