In China, the wastewater produced by electronics, photovoltaic, inorganic fluorine chemical industry, coal mining, coal based chemical industry generally has the problem of exceeding fluoride. As a new method of wastewater fluoride removal, there are problems such as large dosage and sludge production. Preparation conditions of the defluoridation agent were designed and optimized by response surface BBD method, and the defluoridation performance was compared with that of common coagulants. Scanning electron microscopy (SEM) and X-ray powder diffraction (XRD) were used to characterize and analyze the defluorination agents at different preparationstages. The mechanism of defluorination was explored in combination with the residual element level and the utilization rate of each elementin the supernatant after treatment. The results show that the optimal preparation conditions for defluorination agents are n(M) / n(Si) (Mrefers to the total amount of metal) is 44.91, n(Al) / n(Mg) is 40.64, and n(Al) / n(Fe) is 34.92. Under these conditions, when thedosage of defluorination agents prepared is 1.35 g/ L, the fluoride concentration can be reduced from 20 mg/ L to 0.71 mg/ L, which is below the limit of 1.0 mg/ L of GB 3838—2022 Water Environmental Quality Standard Class III standard of Surface. The fluoride removalrate reaches 96. 45%, and the correlation coefficient R2 of the model established by response surface method is 0. 969 0. For thefluorine-containing water samples with initial fluorine concentration of 10-200 mg/ L, the fluoride removal agent is added proportioned,and the residual fluorine concentration in the supernatant is all less than 1.0 mg/ L. The order of defluorination performance with common coagulants is: defluorination agent >PAC>PAFC>PFS. SEM and XRD analysis show that the morphology and structure of the defluoridation agents are changed, and a variety of polyhydroxyl polymers are formed through reactive polymerization. The ion exchange occurrebetween these polyhydroxyl polymers and fluoride ions, and the fluoride ions are removed. Based on the analysis of the residual elements inthe supernatant and the concentration of metal elements in the defluorination reagent, the element utilization rates of aluminum, silicon,iron and magnesium are 99. 98%, 97. 16%, 92. 22% and 18. 39%, respectively. The defluorination reagent is effective and suitablefor many kinds of industrial wastewater containing fluorine.