The invention discloses a preparation method of a gastroenteritis virus monoclonal antibody biological immune preparation, and belongs to the technical field of biological pharmacy. The preparation method comprises processes of TGEV (transmissible gastroenteritis virus) monoclonal antibody preparation, traditional Chinese medicine extracting solution preparation, and TGEV monoclonal antibody and traditional Chinese medicine extracting solution synthesis. The preparation method comprises the following steps: injecting paraffin oil into a mouse peritoneal cavity, injecting hybridoma cells on 6th-9th days, extracting peritoneal dropsy on 7th-15th days, and centrifuging at 2500-3500rpm for 8-12min, so that the supernatant TGEV monoclonal antibody is obtained; soaking 1 part of radix isatidis powder in 8-12 parts of water for 7-15h, keeping the radix isatidis powder in a water bath at 50-70 DEG C for 8-12min, concentrating filtrate at 60-70 DEG C under negative pressure of 7-8Kpa, adding ethanol until ethanol concentration is 70-90% and reserving a supernatant, so that the traditional Chinese medicine extracting solution is obtained; and mixing the TGEV monoclonal antibody and the traditional Chinese medicine extracting solution at the volume ratio of 1 to (0.8-1.2), so that a finished product is obtained. The preparation disclosed by the invention, as an anti-infection medicine, is pure natural, free from drug residues, free from drug tolerance and free from toxic and side effects, and the preparation is significant in effect.