Segment wood cultivation should use good strains with strong resistance, rapid bacterial growth, good mycelial growth, high yield, good quality and good flowering appearance. Before use, strict inspection of strain quality is required. The standard of high-quality black fungus cultivars; the mycelium grows robustly, the tip is neat, the mycelium is thick white, and the hyphae secrete a light-brown pigment after they reach the bottle, and there is a colorless water drop in the bottle wall. If the mycelium is dry or the medium shrinks, there is yellow water at the bottom of the bottle, indicating that the hyphae have become old and cannot be used. If there are black, yellow and other variegated colors on the strains or on the bottle mouth, it indicates that the strains have been infected by bacteria and should be eliminated immediately.