This present invention discloses an integrated method of cyclic utilization of energy grasses comprising the steps of generating biogas residue from the energy grasses, growing edible mushrooms from the biogas residue, producing livestock or poultry feeds from the spent mushroom culture medium, feeding livestock with the feeds, and producing organic fertilizers from the manure of the livestock or poultry. The method, by producing biogas, edible mushrooms, feeds, livestock or poultry, and organic fertilizers, makes an integrated and cyclic use of energy grasses and aforementioned products. This invention will help achieve the goal of cyclic use of energy grasses with great efficiency.
