Mountain mudslides have emerged as one of the main geological dangers in the Yanshan region of China as a result of excessive rains. In light of this, a multi-step debris flow hazard assessment method combining optimal weights and a topological object metamodel is proposed based on game theory ideas. First of all, based on the geological environment research in Yanshan area, this paper determines the mudslide danger evaluation indexes according to the field investigation and remote sensing image data, then combines them with the theory of topological object element evaluation, utilizes the idea of game theory, and carries out the optimal combination of the weight coefficients derived from hierarchical analysis and the CRITIC method to obtain the final comprehensive weights of the indexes, and forms the combination-assigning topological object element of the mudslide danger topological model. The results suggest that improved weight coefficients can increase topological evaluation precision, which is more in line with objective reality than the traditional method and has some application utility.

Heavy rainfall induces shallow landslides in the mountainous areas of China. There is a need for regional slope stability prediction to reduce the damage to infrastructure, residents, and the economy. This study attempts to demarcate areas prone to rainfall-induced shallow landslides using the transient rainfall infiltration and grid-based slope stability (TRIGRS) model under different rainfall conditions. After inputting the engineering geological and geotechnical characteristic data of the area in China, the slope stability was simulated and verified by a deformation monitoring landslide. The slope stability gradually declined under the influence of precipitation from 5–8 July 2021. Slope stability gradually decreased under the predicted rainfall intensity of 60 mm/d for 6 days. The percentage of the slope area with a factor of safety (F_S) less than 1.0 increased from 0.00% (1 d) to 3.18% (6 d). The study results could be used for hazards mitigation in this region.