Abstract: This study collected and analyzed 5 types of 80 water samples from central Lu'an coal deposit to identify the hydrogeochemical characteristics by Piper Plots.The Cluster analysis method (Ward method) showed the obvious clustering and the partial mixing of ordovician limestone water and limestone water,while sandstone water was hard to separate from the other two. Bayes model was used to construct the discriminant functions of different water sources (self-test accuracy 91.5%) and to test the 19 samples of mine water inrush. 12 samples from roof sandstone, 4 samples from ground water and pore water and 3 samples from limestone water was then recognized. Water samples with low posterior probability (less than 80%) could indicate the mixing of the water sources.