The invention relates to a hair washing and bathing two-in-one washing lotion for children and a preparation method thereof. The shampoo comprises sodium methyl cocoyl taurate, sodium laureth sulfate,sodium trideceth sulfate, cocamidopropyl betaine, sodium lauroyl oat amino acid, sodium cocoyl apple amino acid, water, polyquaternium-10, amylopectin, a soapberry peel extract, a tea seed extract, dicocoyl dimethyl ammonium chloride, butanediol, an amur corktree bark extract, a coptis root extract, a radix sophorae flavescentis extract, a rhus semialata gall extract, a cnidium monnieri seed extract, a zanthoxylum bungeanum peel extract, a camphor tree rhizome extract, sodium chloride, phenoxyethanol, ethylhexylglycerin and the like. According to the washing lotion, various natural plant extracts are used as skin conditioners, so that irritation to skin is reduced, and meanwhile, the washing lotion has a relatively strong cleaning function; and the preparation method is easy to operate, the process is easy to control, and large-scale production is facilitated.