The invention discloses a Belgium raspberry soil acidity biological improver and a preparation method thereof. The Belgium raspberry soil acidity biological improver is prepared through using the following raw materials, by weight, 35-45 parts of pine wood chip, 15-20 parts of tobacco leaf leftover, 10-15 parts of tea leave residue, 8-12 parts of beer residue, 5-10 parts of rice bran, 3-5 parts of garlic leaf, 2-4 parts of nidus vespae, 1-2 parts of orange peel, 2-3 parts of Common Threewingnut Root, 1-2 parts of balsam pear leaf, 1-3 parts of rhododendron, 5-10 parts of meerschaum powder, 4-7 parts of bentonite, 3-5 parts of vulcanic ash, 20-30 parts of polyvinyl alcohol, 10-15 parts of hydroxyethyl cellulose and 4-8 parts of boric acid. The soil improver can improve the pH value of soil to make the soil reach blueberry growth conditions. The soil improver contains a plurality of water retention and sterilization components, organic matters and functional microbes, so the soil improver improves soil, increases the content of organic matters in the soil, improves the water retention and fertilizer conservation performances of the soil, sterilizes and disinfects the soil, inhibits the growth and breeding of harmful microbes, reduces the appearance of soil-borne diseases and insects pests, and provides a comfortable growth environment for raspberries after the soil improver is applied to the soil.