The invention discloses a pig feed and a preparation method thereof. The pig feed includes the following components in parts by mass: 200 to 215 parts of corn flour, 70 to 80 parts of soybean meal, 45to 55 parts of bran, 15 to 25 parts of pine needle powder, 1 to 3 parts of mirabilite, 0.5 to 2.5 parts of zeolite powder, 1 to 5 parts of fufang banmao capsules, 10 to 17 parts of silkworm excrement, 0.5 to 1 part of baicalin-copper complex, 0.5 to 2 parts of whey powder, 5 to 12 parts of citric acid, and 11 to 17 parts of vitamin E. The invention adopts the corn flour, soybean meal powder, bran, pine needle powder, mirabilite, zeolite powder, fufang banmao capsules, silkworm excrement, baicalin, copper complex, whey powder, citric acid and vitamin E as raw materials, which are prepared a through reasonable matching system into the pig feed to improve the immunity of pigs and the pig feed has a significant promotion effect on the growth of pigs.