Abstract: An apparatus for treating fluorine-containing wastewater includes a first reactor configured to be injected with a water-soluble calcium salt and fluorine-containing wastewater to produce a water-insoluble calcium salt; a second reactor configured to be injected with a first effluent from the first reactor, a water-soluble aluminium salt and carbonated water to produce a water-insoluble aluminium salt; a third reactor configured to be injected with a second effluent from the second reactor and a polymer coagulant to coagulate the water-insoluble calcium salt and the water-insoluble aluminium salt mediated by the polymer coagulant; and a sedimentator configured to be injected with a third effluent from the third reactor and to sediment the water-insoluble aluminium salt and the water-insoluble calcium salt coagulated in the third effluent by solid-liquid separating the third effluent.