Tianwei Yingli New Energy Resources Co., Ltd., located in China, mainly engaged in silicon solar cell production and sales. Fluoride wastewater mainly came from cell production. Original facilities discharged fluoride wastewater, through Chemical precipitation process. Discharged fluoride wastewater could be up to standard. But the cost of wastewater treatment was high, especially in the low concentration wastewater. To save the water resources and reduce the cost, the classified collection was implemented, then used double pass RO to treat low concentration fluoride wastewater. Before wastewater into RO system, adjusted the pH value and passed activated carbon filter. RO product water instead of tap water entered the pure water preparation system to reuse. The project total investment was about 6.7 million Yuan, treating wastewater was 4320 m3/d. Net income of 3.06 million Yuan/a, and static payback period is 2.2 years. The economic benefit was remarkable.