Magnetic coagulation sedimentation tank is an ultra-efficient precipitation deep water purification technology upgraded on the basis of high efficiency sedimentation tank process and its process flow chart is shown below. Introduce magnetic particles into the water purification process of efficient flocculation sedimentation tank, combine insoluble pollutants such as algae, tiny suspended matter, colloids, bacteria, etc., in the water with particle magnetic powder through flocculation, attraction adsorption, charge adsorption, bridging ,net trapping (magnetic powder specific gravity 5.2)forming a larger volume and density of magnetic floc strengthening the flocculation effect. It can capture the pollutants with smaller particle sizes, making the flocs settle quickly and water purification effect excellent. The effluent is clear and transparent. The sludge in the sedimentation tank is pumped back to the magnetic powder sludge separation system, and the magnetic powder is recycled and used, and the separated sludge is discharged into the sludge tank for dewatering treatment.