The invention relates to a core premix for organic beef cattle, which comprises the following components in percentage by weight: 10-40% of compound galenical preparation, 10-40% of compound enzyme preparation, 10-30% of compound micro-ecological preparation, 20-40% of natural mineral substances, 15-30% of natural vitamins and 5-30% of other preparations. The product can be mixed with organic crop straws, corn, cakes, wheat bran, grass powder, iodized salt, bone powder, calcium powder and the like in certain proportions to be used as a diet for the beef cattle; and by feeding the beef cattle with the diet all year round, not only the immunity of the organic beef cattle can be improved in the feeding process, but also the quality and taste of the beef are improved. Because the product uses the galenical preparation of a plurality of natural traditional Chinese medicines such as cordate houttuynia, honeysuckle flower, radix astragali, forsythia, tuckahoe, fleece-flower root, atractylodes rhizome, white atractylodes rhizome, hawthorn, liquorice and the like as additives to replace the western medicines and antibiotics, uses the compound enzyme preparation to improve the feed utilization ratio and uses the compound micro-ecological preparation to improve the intestinal tract environment of the beef cattle, thus ensuring the food safety of the organic beef.