A method for co-producing molded food-container pulp and fulvic acid from cotton stalk, which belongs to the field of comprehensive utilization of crop straw resources. The method adopts digesting, defibering and bio-treating measures to remove pectin and hemicellulose and other anionic waste generating sources in cotton straw raw materials to obtain a pulp with low beating degree; and retains part of lignin to help form oil-proof and waterproof film of a molded food-container and improves the stiffness and water filtration of the molded food-container and increases a yield of fiber pulp; adopts ammonium sulfite method to pulping to meet fiber requirements while obtaining fulvic acid.