[Background] West Nile fever is widely prevalent in the world, the risk of West Nile fever spreading to China has increased. The rapid detection method of West Nile virus (WNV) was studied to establish the method reserve for West Nile virus detection. [Objective] To establish a reverse transcription recombinase aided amplification (RT-RAA) assay for detection of WNV. [Methods] The primers and probes were designed based on the conserved genome sequence of WNV. An RT-RAA assay of WNV was constructed, and the reproducibility, specificity and sensitivity of the assay were evaluated. [Results] The RT-RAA assay had a constant temperature throughout the amplification reaction, the reaction temperature was 39 °C. The detection time was less than 20 minutes and the detection sensitivity could reach 10 copies. The method had excellent specificity as it didn’t have cross amplification with other arbovirus such as chikungunya virus, dengue virus, Japanese encephalitis virus and Yellow fever virus. The results of sample detection also meet the expectation. [Conclusion] The RT-RAA assay of WNV established in our study was rapid, specific and sensitive. It can be used for rapid detection and epidemiological surveillance of WNV at the port.