Abstract: The present invention discloses a dual-molecular DNA vaccine composed of viral antigen and immunization coactivator, which relates to the technical field of biomedicine. The said vector is a DNA plasmid; the viral antigen is any viral immunogenic (antigen) molecule; the immunological activator is a kind of T cell costimulators. The vaccine disclosed in the present invention is that two gene fragments expressing the T cell costimulator and the viral antigen molecule are constructed into one plasmid DNA and will be co-expressed in a cell at the same time to activate the systemic immune response through the two signalings. The dual-molecular DNA vaccine also is a novel platform of vaccine technology, using for development of multiple vaccines to prevention from various infectious diseases. Especially, a dual-molecular DNA vaccine with the SARS-CoV-2 S antigen and T cell costimulator can be constructed through this technology platform to prevent and control global pandemic COVID-19.