This kit uses double antibody sandwich immunoassay to combined detect specific antigens to SARS-CoV-2, Influenza type A and/or type B in human throat or nasal cavity. For COVID-19 antigen detection, the membrane was precoated with SARS-CoV-2 specific antibody on the test zone and goat anti mouse IgG antibody on the control zone. During the test, the colloidal gold labeled specific antibody bind to the SARS-CoV-2 in the sample to form immune complexes. The immune complexes move forward along the cassette by chromatography. The SARS-CoV-2 in the immune complexes will be captured by the pre-coated specific antibody of SARS-CoV-2 on the test zone to produce a visual red color line. Regardless of the presence of SARS-CoV-2, as the mixture continues to move across the membrane to the control zone, the complex is captured by immobilized goat anti mouse IgG antibody to form a distinct red line. For Influenza detection, The Influenza type A and type B specific antibodies was separately pre-coated onto the test zone of the membrane as the test line A and test line B, and goat anti mouse IgG antibody on the control zone. During the test, the colloidal gold labeled specific antibodies bind to the Influenza type A and type B in the sample to form immune complexes. The immune complexes move forward along the cassette by chromatography. The Influenza type A in the immune complexes will be captured by the pre-coated specific antibody of Influenza type A on the test zone, condense the color to form the test line A. The Influenza type B in the immune complexes will be captured by the pre-coated specific antibody of Influenza type B on the test zone, condense the color to form the reaction line B. The color of line is positive correlated with the amount of SARS-CoV-2 in specimen. Regardless of the presence of Influenza type A and/or type B, as the mixture continues to move across the membrane to the control zone, the complex is captured by immobilized goat anti mouse IgG antibody to form a distinct red line.