The artificial sand and stone processing plant has always been a major pollutant discharge household in hydropower station construction, and the problems of dust and waste water are more prominent. In order to solve the problem of waste water, the artificial sand and stone processing system often uses the wet production process, combined with the sewage treatment facilities to treat the waste water produced by the system, and the pollution particles are precipitated and dehydrated again. The proper measures can realize the zero discharge of waste water. The treatment method of flocculation sedimentation and mechanical dehydration is often used in domestic sand and stone processing system wastewater. The key of the treatment process is flocculation sedimentation, and the control of sludge floc formation speed and separation effect. This paper introduces a new flocculation and sedimentation technology “tower type cyclone stabilizing cylinder concentration technology”. This technology absorbs the advantages of tower type sedimentation technology and cyclone type sedimentation tank technology. By setting up mixed flow tank, stabilizing cylinder and other structures, and combining with field flocculation test and technical fine-tuning, the optimal dosage of flocculant is determined, so as to control the formation speed and separation effect of sludge flocs in a relatively ideal range Status. The process has been successfully applied in the no wastewater treatment of the sand and gravel processing system of Batang hydropower station, and good results have been achieved, which is worthy of reference.