A method for treating fluoride-containing waste water is disclosed. The method includes, first, inducing fluoride-containing waste water and calcium compound into a crystallization reaction tank having a plurality of crystallizing webs so as to conduct a reaction between the fluoride-containing waste water and the calcium compound to form calcium fluoride crystals on the crystallizing webs; meanwhile, stirring the fluoride-containing waste water and the; then, discharging the fluoride-containing waste water out of the crystallization reaction tank for conducting a successive treating step.