Abstract: Mine flood accidents are closely related to the geological structure of the minefield. Scientific evaluation of the complexity of the mine structure is of great significance to the safe mining of the mine. Taking Xiaoyun Coal Mine as the research object, Select the value of fault fractal dimension, fault density, the number of fault pinch points and intersections, and fault strength index as the evaluation indicators that affect the structural complexity of the mine,An improved stacking algorithm (Stacking) based on gray correlation degree (GRD) for index weighting calculation, Obtain the weight of the main controlling factors of the mine structure complexity, and establish the quantitative evaluation model of the mine structure complexity. The study area is divided into structural failure zone, structural influence zone and stratum intact zone. The core sampling rate verifies the validity and rationality of the zoning pairs of structural complexity. The results show: The evaluation results are consistent with the core adoption rate verification results, and are basically consistent with the actual exposure of the coal mine, which proves the rationality of the evaluation model and provides a guiding basis for the efficient and safe production of the mine.