The running conditions of deep defluorination by hydrothermal crystallization in the fluoride-containing wastewater treatment engineering of a photoelec. enterprise glass thinning is introduced,as well as,the effect of defluorination and economic indexes are analyzed.The results show that the fluorine content of effluent can be controlled below 6 mg/L,and the cost of treatment is 13.32 yuan per ton.The quality of effluent can remain steadily and meet the first grade requirement of China's national integrated wastewater discharge standards,showing a prospect of promotion.