The invention provides fattening pig feed with a function of immunity improvement. The fattening pig feed is composed of a basic material, an auxiliary material and an additive material. The basic material is made of kidney beans; the auxiliary material is made of corns, potatoes, broomcorn, mung beans, bran, oats, radish leaves, cucumbers, tomatoes, sweet potatoes, apple peels, banana peels, polygonum chinense, brassica napobrassica, bean sprouts, caraway, water chestnuts, cauliflowers and pericarpium granati; the additive material is made of fructus amomi, medicated leaven, liquorice, Chinese dates, dark plum fruit, poria cocos, pericarpium citri reticulatae, burdock, rhizoma dioscoreae, hawthorns, radix ophiopogonis, fructus oryzae germinatus, dioscorea opposite, rehmannia glutinosa, lotus root, dried lily bulb, pumpkin seeds, cuscuta chinensis, rhizoma cibotii, rhodomyrtus tomentosa, rhizoma drynariae, cynomorium songaricum, fructus cannabis and platycladi seeds. The fattening pig feed has the advantage that the fattening pig feed is environment friendly and harmless and capable of guaranteeing daily growth needs of pigs; since the feed contains Chinese herbal medicines, internal body functions of the pigs can be slowly conditioned in daily feeding, disease resistibility of the pigs is improved, and marketing rate is increased due to acceleration of growth of the pigs.