Chagan　Lake　is　located　in　the　area　of　Western　Jilin　for　which　waterways　have　high　fluorine　content.　Because　of　the　construction　of　water　conservancy　projects　and　agricultural　irrigation　areas,　the　groundwater　replenishment　and　drainage　conditions　there　have　changed.　Groundwater　test　data　were　used　to　analyze　the　status　of　groundwater　fluoride　with　this　changing　hydrodynamic　gradient.　The　paper　established　a　health　risk　assessment　model　based　on　triangular　fuzzy　number.　The　results　show　that　the　samples　of　phreatic　water　and　confined　water　with　excessive　fluoride　content　accounted　for　68.74%　and　29.4%,　respectively.　Samples　that　exceeded　standards　of　fluoride　content　were　mainly　distributed　in　the　northwest　and　southwest.　The　chemistry　of　phreatic　water　is　more　complicated　than　that　of　confined　water.　The　water　quality　categories　are　mainly　poor　and　very　poor.　The　formation　of　major　anions　and　cations　was　mainly　controlled　by　evaporation　and　rock　weathering.　It　was　also　found　that　non-carcinogenic　risks　of　fluoride　in　phreatic　water　are　greater　than　those　in　confined　water.　The　risk　indices　for　children　and　adults　were　[1.1,　1.6]　and　[0.6,　0.9],　respectively　(alpha　=　0.8).　The　non-carcinogenic　risk　assessment　model　based　on　triangular　fuzzy　numbers　has　a　higher　reference　value　than　that　of　traditional　models.