Abstract: The resources of corn straw were rich in Chongqing Alpine Regions, but many were burned, resulting in a waste of resources. Fermentation could take advantage of existing straw fermented into rich in protein, vitamins and inorganic salts silage. Silage additive had now been widely applied in straw silage. In order to study the effects of different microbial preparations on the quality of corn straw silage, corn straw of Chongqing Alpine Regions carried out fermentation of silage by adding different percentages of formic acid, EM fungi and cellulase. The results showed that during the fermentation process of corn silage, adding formic acid, EM fungi and cellulase could improve and increase the quality and nutrient value of silage. The effects of 3 mL/kg formic acid and EM fungi+cellulase were the best, obtaining good silage corn stalks, improving the quality of silage fermentation. pH values were 4.33, 4.28, lactic acid contents were 3.27% , 4.06% , crude protein contents were 2.99% , 2.34% , and the sensory evaluation of silage were excellent. Both treatment methods could available to the ideal corn stalk silage, improving the fermentation of corn stalk silage quality, being used as a basis for silage corn stalks in Chongqing Alpine Regions.