The invention discloses a feed additive and a feed applying the same. The feed additive contains the following components in parts by weight: 100-200 parts of bacillus subtilis spore powder, 200-300 parts of clostridium butyricum spore powder, 80-150 parts of mannan oligosaccharide, 75-125 parts of organic chromium and 0.5-1.0 part of papain. When the compound feed applying the feed additive is used for feeding growing-finishing pigs with the weight of 60Kg until the pigs are put into the market, the production performance of the pigs can be effectively improved, the feed conversion ratio is increased, the carcase fat deposition is reduced, the longissimus dorsi drip loss is reduced, the backfat thickness is reduced, an eye muscle area is increased, the meat tenderness is improved, and the cultivation cost is reduced.