The invention relates to natural plant hair growing and blacking liquid and a preparation method thereof. The hair growing and blacking liquid comprises pterocarya stenoptera, hoantchy root, angelica, ginseng, prepared fleece flower root, prepared rhizome of rehmannia, herba ecliptae, Cacumen biotae, safflower, nutgall, mulberry, medlar, glossy privet fruit and dittany bark; and the preparation method of the hair growing and blacking liquid comprises the following steps of: cleaning the hoantchy root, the angelica, the ginseng, the prepared fleece flower root, the prepared rhizome of rehmannia, the herba ecliptae, the nutgall, the mulberry, the medlar, the glossy privet fruit and the dittany bark by using water, soaking, carrying out reflux extraction through depressurizing, concentrating, depositing in alcohol, stewing, carrying out refrigerated storage, then, filtering and taking a supernatant; cleaning the Cacumen biotae, the safflower and the pterocarya stenoptera, refluxing by using 60% ethanol, and extracting a concentrated solution; evenly mixing the supernatant and the concentrated solution, filtering and taking a supernatant, namely, obtaining the hair growing and blacking liquid. The hair growing and blacking liquid has the effects of hair growing and blacking, nourishing liver and kidney, replenishing trace elements, invigorating blood circulation to grow new hair and changing white hair into black hair, a scientific formulation, the unique preparation method, and is safe and reliable, remarkable in curative effect, short in period of treatment, and quick in acting.