Banana bacterial sheath rot，caused by Dickeya dadantii，is a significant threat to the production of banana in China.Accurately and quantitatively detecting this pathogen at an early stage is important to control banana bacterial sheath rot.A SYBR GreenⅠreal-time quantitative PCR method was established with specific primers based on the housekeeping gene fusA of D.dadantii and optimized conditions for amplification.Comparisons were made between the result of the established SYBR GreenⅠreal-time quantitative PCR and that of the conventional PCR.The established SYBR GreenⅠreal-time quantitative PCR was used to detect XJ5-1 in banana leaf sheaths and soil samples inoculated with banana bacterial sheath rot bacteria XJ5-1.The results showed that the sensitivity of SYBR GreenⅠreal-time quantitative PCR for detecting the plasmid DNA was 3.3×10^-5 ng/μL，100 times higher than that of conventional PCR.The established method was able to detect XJ5-1 in banana plants with a copy number of 4.31×10³ copies/μL and in soil samples with a copy number of 1.07×10⁹ copies/μL，and in samples of used greenhouse soil inoculated at an inoculum concentration of 1×10³ CFU/mL.The sensitivity of detecting soil samples with the established method was 100 times higher than that with the conventional PCR.It is indicated that the established SYBR GreenⅠreal-time quantitative PCR method is rapid，simple，and sensitive.It will lay a foundation for the early diagnosis and monitoring of banana bacterial sheath rot.