In the Yingqian lead-zinc mine in Jiangxi Province, after the tailings slurry produced by the mine's supporting dressing plant naturally settles through the tailings pond, part of the supernatant water is returned to the dressing plant for recycling, and part is discharged. This is because the mine is adjacent to the Ganjiang Source Nature Reserve and the steep slopes. In the water source area of the lake, the quality of the drainage water outside the dressing plant must meet the lead and zinc pollutant discharge standards (GB25466-2010) before it can be discharged. The lead-zinc mine tailings wastewater has a large volume, complex composition, and difficult treatment. The supernatant water of the slurry has problems such as high concentration of suspended solids, excessive heavy metals and high pH value, and cannot meet the discharge standards. For the treatment of lead-zinc mine tailings wastewater, it is urgent to find efficient and low-cost treatment methods. The HDCY integrated multi-effect clarification system independently developed by Beijing Huade Ventures has completely solved the problem of lead-zinc mine tailings water not being discharged up to standard. The system consists of modules such as coagulation reaction tank, flocculation reaction tank, pre-sedimentation area, inclined tube separation area and medium recovery area. The HDCY integrated multi-effect clarification system highly integrates various technologies that are conducive to solid-liquid separation, such as chemical coagulation, mechanical stirring, loading sedimentation, and inclined tube separation. With the help of reasonable media action and sludge return measures, it maintains the loading efficiency. The sedimentation tank has the advantages of high speed, compactness, good effluent quality, strong impact resistance, and saving operating costs. It also increases the flexibility of operation. Suspended solids, heavy metals and other substances in the water settle in the form of flocs, thereby achieving qualified water discharge effect.