The invention relates to a soybean protein bioactive peptide feed additive containing traditional Chinese medicines and a preparation method of the soybean protein bioactive peptide feed additive, and belongs to the technical field of production of feeds. The soybean protein bioactive peptide feed additive is prepared from the following raw materials in percentage by weight: 2-3% of radix astragali, 3-5% of purslane, 1-2% of glossy ganodermas, 3-5% of dandelions, 1-2% of honeysuckle flowers, 80.4-88.7% of soybean protein powder, 1-2% of lactic acid bacteria, 0.1-0.2% of protease, 0.1-0.2% of cellulase, and 0.1-0.2% of xylanase. The soybean protein bioactive peptide feed additive is prepared through the following steps of crushing and weighing the raw materials, mixing dissolved liquid with the weighed raw materials, performing fermentation, performing drying and the like. The feed additive disclosed by the invention does not contain any substances harmful to livestock and poultry, is free from toxic and side effects, environmentally-friendly and safe, does not contain macromolecular substances, consists of micromolecular substances of biological active peptides and the like, has the effects of promoting growth, being antioxidative, improving the immunity of organisms and reducing diarrhoea rate, can increase the daily gain of the livestock and the poultry and the efficiency of feed utilization, and is particularly suitable for young livestock and young poultry.