The invention discloses tea saponin shampoo and a preparation method thereof. The shampoo takes a natural surfactant tea saponin as a main surfactant, and the tea saponin has good emulsifying, dispersing, wetting and foaming capacities, and has physiological activities of removing dandruff, resisting bacteria, relieving itching and the like. A micelle co-dissolution technology is adopted, a micromolecular amphiphilic surfactant is compounded to serve as a micelle inducer, macromolecular micelles are converted into micromolecular micelles, and the defects that the surfactant is prone to remaining and not easy to wash are overcome; and on the basis of the physiological activities of the tea saponin, camellia oil, a rosemary extracting solution, a cacumen biotae extracting solution, a white willow bark extracting solution, a chamomile extracting solution, a gentian extracting solution, a witch hazel extracting solution, octacosanol, squalene and other naturally extracted effective functional components are added to prepare the shampoo which is green and natural, has the effects of killing bacteria, relieving itching and removing dandruff, and has excellent conditioning performance onhair and scalp.