Given　the　ambiguity　of　the　type　and　classification　in　groundwater　quality　standards,　this　paper　based　on　fuzzy　mathematics　theory,　take　TDS,　fluoride　and　other　components　as　the　nine　evaluation　factors,　determine　its　weight　according　to　the　pollution　of　different　factors　on　water　quality;　using　fuzzy　membership　to　describe　the　classification　boundaries　of　the　evaluation　in　water　quality.　Established　a　number　of　pollution　assessment　factors　of　fuzzy　sets　such　as　evaluation　set,　membership　function　and　weight　set;after　the　compound　operation　of　fuzzy　matrixes,　using　the　maximum　membership　degree　law,　to　evaluate　the　groundwater　quality　of　a　monitoring　well　in　study　area,the　conclusions　are　objective.