The invention relates to a composite premix for a pig, belonging to the field of premix. The premix provided by the invention comprises the following main ingredients of: vitamin A, vitamin D3, vitamin E, vitamin K3, vitamin B1, vitamin B2, vitamin B6, vitamin B12, nicotinic acid, D-calcium pantothenate, biotin, choline chloride, copper sulfate, ferrous sulphate, zinc sulfate, manganese sulfate, potassium iodide premix, sodium selenite premix, an antioxidant, a composite microbioecological agent, bentonite and rice chaff. The premix provided by the invention has the advantages of reasonable prescription, no addition of antibiotic, multiple probiotics and high viable bacteria content; and it is proved by an animal breeding laboratory that the composite premix has an ideal breeding effect and can ensure that the pig has a high yield, a fast weight growth and high meat ratio. The composite premix provided by the invention has a good promoting effect on pig growth and health condition, can satisfy requirements on the current broad masses of farmers, and is suitable for developing green and healthy breeding and producing pollution-free livestock products.