Abstract: The study established a SYBR Green I real-time fluorescence quantitative PCR assay for detecting orf virus. Using Beacon Designer 7.9 software to design a pair of specific primers based on the VIR gene of the orf virus in the Genbank (accession number.KF666563.1). The result showed that it would specifically detect orf virus, but wouldn't detect other sheep and goat bacteria and viruses. The detection limit of the method was 100 copies·μL^-1 and the detected Ct values of intra-and inter-variation were all less than 2%. Using the assay to detect 39 clinical samples, the positive rate was 94.9% (37/39). The above results indicated that the assay had a high specificity, sensitivity and repeatability, which could be used to detect orf virus and conduct epidemiological investigation.