The invention discloses a mixed type acidity regulator for feed additives. The mixed type acidity regulator is characterized by being prepared from the following components in parts by weight: 25-35 parts of formic acid, 15-25 parts of ammonia water, 8-15 parts of lactic acid, 5-8 parts of acetic acid, 3-5 parts of citric acid and 28-35 parts of silicon dioxide. According to the mixed type acidity regulator disclosed by the invention, firstly various acid components are added into a reaction kettle for sufficient reaction and fusion, and the fused acid components are shifted into an ion state and enter a high uniform state. The mixed type acidity regulator for the feed additives, produced in a manner, has extremely high mixing uniformity, and various acid molecules are highly dispersed, so that the situation that effective components uniformly enter feeds and then the feeds are eaten is facilitated, the situation that animals stably and uniformly digest the feeds is guaranteed, increase of culturing benefits is facilitated, and the mixed type acidity regulator is a development direction of future acidity regulators and other additives. In addition, the liquid acidifying agent disclosed by the invention is safe to use, free from toxic and side effects on the growth of the animals, free from residues, and low in corrosion to animals, human bodies and production equipment.