The invention discloses a cassiabarktree twig extract-containing whitening cosmetic preparation method, which comprises: 1, adopting ethanol to extract cassiabarktree twig, Chinese thorowax root, common macrocarpium fruit and rose to obtain an extract; 2, carrying out heating mixing melting on C18 alcohol, inositol hexaphosphate, glycerol and stearic acid, and adding tert-butylhydroquinone to dissolve to obtain an oil phase; 3, adding borax, glyceryl monostearate and refined water to the Chinese herbal extract, and mixing to obtain a water phase; and 4, adding the oil phase to the water phase, carrying out emulsification, and adding flavor to obtain the cosmetic with effects of whitening and spot removing. The cassiabarktree twig extract-containing whitening cosmetic has effects of skin metabolism improvement, skin blood circulation promotion, skin nutrition increase, effective free radical removal, pigmentation elimination, skin wrinkle and color spot fading, and delicate, smooth, white and flexible skin achievement.