Disclosed herein are recombinant antibodies or the fragment thereof for detecting severe acute respiratory syndrome coronavirus (SARS-CoV). According to some embodiments, the SARS-CoV is SARS-CoV-1. According to some alternative embodiments, the SARS-CoV is SARS-CoV-2. Also disclosed herein are a kit comprising the recombinant antibodies, and a method for diagnosing the infection of SARS-CoV by using the recombinant antibody or the kit.