Dam leakage treatment is a crucial work in the reinforcement of reservoir dam. The leakage problems caused by complex unfavorable geological bodies and concrete’s deep micro-cracks in water conservancy and hydropower projects are detrimental to the mechanical and seepage stability of reservoir dams. How to effectively deal with them still remains a huge problem in hydraulic engineering. Ordinary cement or ultra-fine cement grouting is often difficult to achieve the desired treatment effect, whereas chemical grouting appears a more effective technical approach. Under the background of some major national water conservancy and hydropower projects, Changjiang (Yangtze) River Scientific Research Institute has developed CW series high-performance chemical grouting materials and corresponding grouting equipment as well as fine control techniques over years of innovation, hence forming a complete set of novel chemical grouting technology for reservoir dam reinforcement. The technology has been applied to over 100 water conservancy and hydropower projects in China and abroad, which effectively ensures the safe operation and comprehensive benefits of projects, and produces huge social, economic and ecological benefits.