As a marine bacterial pathogen, Photobacterium damselae subsp. damselae (PDD) is distributed in seawater worldwide. It can infect different animals as well as humans, even cause deaths. The highly conserved regions of PDD mcp gene on chromosome and dly gene on plasmid were selected as the target fragments to design the specific primers. Recombinant plasmid standard was prepared based on the primers. With GENECHECKER UF-150 qRT-PCR instrument as the platform, a fluorescence-based quantita-tive real-time PCR (qRT-PCR) method was established for the detection of PDD. This method can specifically detect PDD and dis-tinguish the highly virulent strains. Additionally, the test results can be qualitatively judged by visualization, while the quantitative detection can be achieved through the standard curve calculation. The minimum limit of detection was 1.0×101 copies μL-1, and the detection time was less than 20 min. In summary, this new method has outstanding advantages, such as strong specificity, high sensi-tivity, and low site requirements. It is a rapid on-site detection technology for highly virulent PDD strains.