The invention relates to a preparation method and application of folium lycii oligosaccharides and folium lycii acidic polysaccharides. An ultra-micro pulverization technology is applied to extraction of the folium lycii oligosaccharides and the folium lycii acidic polysaccharides, so that the extraction efficiency of the folium lycii oligosaccharides and the folium lycii acidic polysaccharides and the utilization rate of medicinal materials are greatly improved; integrated efficient preparation of the folium lycii oligosaccharides and the folium lycii acidic polysaccharides is effectively achieved; the folium lycii oligosaccharides and the folium lycii acidic polysaccharides, prepared by the preparation method, can be effectively used for preparing antibacterial medicines or health-care products; the folium lycii acidic polysaccharide I and the folium lycii acidic polysaccharide II are effectively used for preparing anti-tumor medicines.