The invention relates to a method for extracting transfer factors from animal spleens, and mainly aims at providing a method which is applicable to in-scale transfer factor production. The method comprises the following steps of firstly crushing spleen cells to prepare a homogenate, secondly eliminating cell residues in the homogenate, and subsequently extracting the transfer factors, wherein the step of eliminating the cell residues in the homogenate comprises adjusting the pH value to 7.2, adding polyaluminium chloride into the homogenate according to a mass volume ratio of 1%, uniformly stirring, acting for 30 minutes, centrifuging for not less than 30 seconds, repeating centrifuging for three times, adding 0.5% of, 0.4% of and 0.1% of polyaluminium chloride according to the mass volume ratio each time, all uniformly stirring after adding polyaluminium chloride, acting for 30 minutes, primarily filtering the centrifugate, and finely filtering the primary filtrate by using a filtering film with a filtering precision of 0.2 microns so as to obtain the transfer factors. According to the method, the polyaluminium chloride sediment is adopted to eliminate the spleen cell residues in a breakthrough, so that the production method is applicable to in-scale production of transfer factors which are high in effective content and good in biological activity.