Abstract: Abstract: In order to improve the evaluation accuracy of coal floor water damage, taking the evaluation of coal floor water hazard in the study area as an example, the vulnerability index method and water inrush coefficient method based on the GIS technology are comparatively analyzed, and the better evaluation method is selected. Through the use of GIS technology this article，using the vulnerability index method, thematic map of main control factors was established under the three levels--confined aquifer, geological structure and floor aquitard. The analytic hierarchy process was used to determine the weights and thematic maps were superimposed to generate the zoning map. When using water inrush coefficient method we got the result of evaluation partition. we can conclude that the GIS-based AHP Analytic Vulnerability Index method is closer to the actual situation and more instructive for safe coal mining after comparing the accuracy of the two methods.