Abstract: In order to realize the water quality detection of coal mine quickly and accurately, it used fuzzy comprehensive evaluation principle to judge water quality types, the principle was based on deviation weighted method. The algorithm model of fuzzy comprehensive evaluation was constructed in accordance of groundwater chemical characteristics in Xingtai Coal Mine. It was programmed by the language C^# and applied to the rapid water quality detection system successfully, which was based on the platform of Visual Studio 2008 and SQL Server 2005. It provided a decision support method for coalmine water hazard prevention and control.