The water content of river and lake sediments is high, the volume is large, and they are rich in a large number of pollutants. Therefore, the treatment of polluted sediments after dredging has always been a technical challenge for urban river and lake pollution control. The core technology of this achievement is the deep dehydration technology for conditioning polluted sediments. In addition to adding flocculants to treat the properties of polluted sediments, stabilizers must also be added to seal and stabilize heavy metal elements in the polluted sediments. The entire process flow is very environmentally friendly. This process distinguishes between heavily contaminated sludge, moderately contaminated sediment, and lightly contaminated sediment based on the degree of pollution of the sewage reservoir bottom mud: heavily contaminated sludge is treated and then transported to designated places for permanent sealed storage; moderately contaminated sediments can be sealed and stored nearby before being covered with planting soil for greening and island creation; lightly contaminated sediments undergo harmless treatment. Compared with the original lake bottom mud, the sludge processed by this process has lost a large amount of moisture. The volume has been significantly reduced. The moisture content of the sludge after two months of treatment is only about 50%, and the process effect is very ideal.