1. The high concentration fluorine-containing wastewater was treated by calcium salt precipitation method. Lime milk was added to the wastewater, and polyacrylic acid was selected as flocculant, so that fluoride ions and calcium ions were precipitated and removed. 2. Features: simple method, convenient treatment, low cost, slow sludge settling, difficult dehydration, and it is difficult for the treated effluent to reach the national standard.