Environment friendly mushroom companion(mushroom-stick epidermis protective agent) newly developed by Fujian Province Tiantuo Biotechnology Co.,Ltd can effectively solve the problem that there is pollution when using plastic water conservation film and paraffin in the process of Shiitake cultivation. The protective agent is white powder, belongs to a water carrier that adjust inner ester for pure natural plant source growth, can absorb water several dozens of itself weight, after water absorption it becomes cotton-like gel. The product is green, environment friendly and without residue. After large area application in Shiitake cultivation in Gutian county, Fujian province it is proved that: after film formation can effectively prevent water evaporation, restrain the invasion of other harmful mould, greatly improve mushroom quality, and remarkably increase both production and income. It has characteristic of safe, environment friendly, strong protective properties, promoting growth and saving both time and labor. Through the test by Fujian Province Edible Mushroom Testing Center showed that mushroom-stick epidermic protective agent is safe to human body. The application of it conforms with related national standard and will not produce any harmful effect on Shiitake eating.