The invention belongs to the technical field of biomedical materials, and particularly relates to an extraction method of bovine tendon type I collagen. The extraction method comprises the following steps: washing fresh bovine tendons, removing fat, aponeuroses and muscles, cutting the bovine tendons into tendon blocks, soaking the tendon blocks with a sodium bicarbonate aqueous solution, cleaning, and airing to obtain pure bovine tendons; adding the pure bovine tendons in a triethanolamine-containing myristic acid solution for soaking, and cleaning and airing the soaked pure bovine tendons; adding the aired pure bovine tendons in liquid nitrogen, and grinding into powder to obtain bovine tendon powder; taking the bovine tendon powder, adding the bovine tendon powder in an acetic acid-sodium acetate buffer solution, adding pepsin and squalene, uniformly stirring, carrying out enzymatic hydrolysis, then adding glycol dimercaptoacetate, and carrying out oscillating reaction to obtain enzymolysis liquid; and carrying out salting-out and dialysis on the enzymolysis liquid to obtain the bovine tendon type I collagen. The preparation method provided by the invention is simple and the equipment requirement is low; and the obtained product is high-purity type I collagen with a triple helix structure, cannot cause mechanical injuries on nervous tissues, and is good in biocompatibility.