The invention discloses a probiotics fermented Xiaoshuan oral liquid and a preparation method thereof. Bifidobacterium and lactobacillus beneficial to human bodies are used for fermenting water extractives of raw medicinal materials, namely astragalus membranaceus, angelica sinensis, root of common peony, lumbricus, ligusticum wallichii, peach kernel and red flower of the Xiaoshuan oral liquid. On the one hand, whole components of the water extractives of the traditional Chinese medicines are retained, and the medicinal materials are saved; on the other hand, after the water extractives are fermented by probiotics in intestinal tract, macromolecular substances are converted in vitro, so that the oral liquid is easy to absorb by human bodies, and the curative effect is improved; furthermore, in fermentation, abundant flavor substances are generated, so that the taste of the traditional Chinese medicine is improved. Experiments prove that the probiotics fermented Xiaoshuan oral liquid is superior to the Xiaoshuan oral liquid prepared by original technologies in shortening blood clotting time and improving mesentery microcirculation.