Pipeline disinfection machine of preparation water dispenser disinfects the pipeline of reverse osmosis membrane and distribution system without corrosion and oxidation, and can extend the service life of purified water system. Less washing times during disinfection (generally 1~2 times), which can effectively save water resources and reduce working intensity. The use of green disinfectant, safe and environmental protection, no residue after disinfection, can reduce the risk of harm to human body and chemical residue.