Abstract: The prevention and control of floor water damage has always been the top priority in coal mine safety. Currently, there is a paucity of research on the prediction and control of water damage during repeated mining activities within closely spaced coal seam groups compared to single-layer operations. The close proximity between upper and lower coal seams leads to secondary superposition failure during repeated mining, exacerbating the challenges associated with effective water control measures.Using 33200 working face of Pingmei 10 mine as a case study, this paper analyzes microseismic event spatial patterns, energy distribution, as well as extensive statistical data resulting from repetitive lower coal seam extraction actions. It identifies key characteristics related to floor microseismic activity under such conditions while proposing a risk assessment system for potential water inrush using entropy weight method.The research results are consistent with the field.The results show that: ① Based on the analysis of the spatio-temporal evolution law of microseism, the warning layer of coal seam floor and its judgment conditions are proposed. The occurrence of this layer and its deep events is a signal of the disturbance of strong aquifer, which is significantly related to water movement and structural activation, and is an important precursor information for microseism to capture the occurrence of water inburst, which can improve the precision of water disaster warning. ② In the close-range repeated mining of the lower coal seam, especially in important nodes, such as water outlet position in the upper coal seam, water increase positionin, deep primary damage zone, the response characteristics of microseismic monitoring indicators including rear influence zone, advance influence zone, and failure depth of the floor are clearly evident. These indicators demonstrate the extent of fracture generation and expansion in the floor rock due to mining activities from both a planar and vertical perspective.③ Taking microseismic event activity double factor, spatial distribution double factor, rupture scale factor as the core, integrating a variety of influencing factors of floor water inburst, applying entropy weight method to construct a quantitative evaluation system of repeated mining floor water inburst risk, which has been proved to be in good agreement with the field.This study provides theoretical insights and data foundation for analyzing the water inrush channel related to damage and rupture at lower floors within close coal seam groups undergoing repeated mining operations. Furthermore, it offers new perspectives for determining failure depth at bottom floors as well as evaluating water inrush risks while aiding in enhancing precision through microseismic monitoring for predicting coal mine floor water damages.