To effectively reduce the consequences and losses caused by tunnel water inrush disasters, a risk assessment method for tunnel water inrush disasters was proposed based on order relation analysis method (G1), criteria importance through intercriteria correlation (CRITIC), and the principle of grey relation vector projection. Building upon a survey of relevant literature and engineering examples, four aspects including strata lithology, hydrogeology, adverse geology, and construction design were considered to establish a quantifiable index system for assessing tunnel water inrush risk. Additionally, to better avoid biases introduced by human factors, the G1-CRITIC method was employed for subjective-objective weighting. By introducing game theory, a combined weight of subjective and objective weighting was obtained to scientifically and reasonably allocate weights to each evaluation index. Finally, quantitative evaluation of tunnel water inrush risk levels was conducted through grey relation vector projection. This risk assessment method was applied to three sections of sample tunnels in Wenbi Mountain 1# Tunnel, assessing tunnels water inrush risks. The results show that the risk level of tunnel sample 3 is Grade IV, while the other two tunnel sections are Grade Ⅱ water inrush risks. The obtained risk assessment levels are consistent with the actual excavation conditions, demonstrating the model's ability to accurately evaluate engineering geological disasters under multiple influencing factors. Comparison with other model results further validates the feasibility and accuracy of this evaluation model.