The invention discloses a recombinant antigen for BVDV (bovine viral diarrhea virus) antibody detection and a rapid detection test strip thereof, mainly aiming at a truncated BVDV NS expression antigen for BVDV antibody detection and a rapid detection test strip for detecting BVDV antibodies. A BVDV NS protein amino acid sequence is analyzed by utilizing epitope analysis software; a fragment with the main epitope is taken; a truncated BVDV NS recombinant antigen is obtained according to the corresponding nucleotide sequence design primer through PCR (polymerase chain reaction) amplification, recombination expression carrier construction and prokaryotic expression, and can be used for BVDV antibody detection after being purified. The rapid detection test strip established based on the truncated BVDV NS antigen has the advantages of convenience in operation, rapid detection, no requirement of a special laboratory and equipment and the like, overcomes the limits of the existing detection method, and can be used for rapid detection and serum epidemiological investigation of the BVDV antibodies.