Abstract: In response to problems of water source contamination, water quality security risk, and the difficult removal of poisonous and pernicious substances such as algae, odor, ammonia nitrogen and arsenic, the National Major Science and Technology Program for Water Pollution Control and Treatment in the 11 ^th and 12 ^th five-year plan periods developed significant technologies covering water regulation, water quality purification, water distribution system and its monitoring and evaluation, advance warning and emergency treatment, and drinking water security control. On this basis, the drinking water insurance multi-barrier process with ozone-GAC and membrane separation as core technologies has been established, and domestic-produced critical equipment and materials realized. Moreover, the drinking water insurance technology system from water source to tap has been established and applied in Taihu Lake Basin and South-to-North Water Diversion Project benefited regions in large scales, leading to an accumulative water supply scale of over 10 million m ³/d and a benefited population of over 80 million, and providing technical support for improvement of the qualified rate of urban water supply quality from 58.2% in 2009 to 96.0% presently. In the meanwhile, the achievements have provided systematic technical support for national urban-rural water supply planning, urban water supply quality supervision and the construction of water supply emergency rescue bases.