The invention discloses a corn straw silage feed preparing technology. A corn straw silage feed is prepared through the steps of preparing a silage pond, collecting and sorting silage feed raw materials, performing cutting-up, adding a feed additive, performing loading, closing over dry substances, performing film coating pretreatment, and performing earth coating for sealed storage. According tothe corn straw silage feed prepared by the corn straw silage feed preparing technology disclosed by the invention, the content of a hazardous substance, namely flavatin, in the feed is reduced, the mildew and rot rate of the feed is reduced, and the mouth feel and the quality of the feed are improved; besides, the silage feed is not liable to decompose due to silage, the silage loading void content is reduced, and favorable anaerobic environment can be created for lactic acid bacteria fermentation, so that fermentation is facilitated; a layer of the dry substances are covered, so that the situation that a large quantity of nutrient components run off along with moisture is avoided, nutrient loss is reduced, and the fragrance of lactic acid of the silage is improved; and the feed additive is added, so that the quality of the silage feed can be improved, the food consumption of the feed is increased, and the palatability of the feed is strengthened.