NOVELTY - Method for cultivating straw mushroom using a tunnel fermentation medium, involves placing 7-8 pts. wt. needle mushroom residues and 2-3 pts. wt. waste cotton into a stirrer, adding 3-6 wt.% quick lime with respect to total culture medium, adding water, mixing and stirring uniformly to obtain culture medium, where water content of the culture medium is maintained to 65-70%, and pH of the culture medium is maintained to 8-9, performing tunnel fermentation, cultivating straw mushrooms by inoculating, spawn running, cultivation, fruiting, harvesting and storing product.    USE - The method is useful for cultivating straw mushroom using a tunnel fermentation medium (claimed).    ADVANTAGE - The method prepares culture medium with improved physicochemical property, is environmentally-friendly as it replaces 70%-80% waste cotton and needle mushroom residue, is performed cost-effectively with less energy consumption. The nutrients of the culture medium are more easily absorbed by the straw mushrooms in the fermentation process, and enables to product increased yield.    DETAILED DESCRIPTION - Method for cultivating straw mushroom using a tunnel fermentation medium, involves placing 7-8 pts. wt. needle mushroom residues and 2-3 pts. wt. waste cotton into a stirrer, adding 3-6 wt.% quick lime with respect to total culture medium, adding water, mixing and stirring uniformly to obtain culture medium, where water content of the culture medium is maintained to 65-70%, and pH of the culture medium is maintained to 8-9, performing tunnel fermentation by stacking the culture medium into a tunnel to a height of 1.5 m, allowing airflow through the tunnel using a fan, regulating circulation of fresh air into the tunnel, discharging or recycling the material from the upper end of the tunnel, performing batch fermentation under controlled oxygen level and temperature, cultivating straw mushrooms by inoculating, spawn running, cultivation, fruiting, harvesting and storing product.