The invention provides a beef liver blood pudding and a preparation method thereof. The beef liver blood pudding is prepared from the following raw materials in parts by weight: 100-110 parts of beef blood, 50-60 parts of beef liver pulp, 90-100 parts of milk, 10-15 parts of tallow, 25-35 parts of barley flour, 30-40 parts of oat powder, 2-3 parts of soybean isolate protein, 2-3 parts of starch, 15-20 parts of onion oil, 2-4 parts of ginger juice, 2-4 parts of white pepper juice, 3-5 parts of sugar and 4-6 parts of salt. According to the invention, fresh animal blood, liver, fat, barley, milk and the like are combined organically so as to prepare the beef liver blood pudding product which is unique in flavor, rich in nutrition and convenient to process and eat; and the beef liver blood pudding is not only excellent in quality and low in price, the preparation method is simple, but also the pudding market is enriched, and a novel approach is provided for the development of animal byproducts.