Abstract: 【 Objective 】The objective of this study is to establish a rapid detection method for PRRSV Nsp2 gene by reverse transcription recombinase-mediated isothermal amplification (RT-RAA) fluorescence. 【 Methods 】Primers and probes of classical strains and highly virogenic strains were designed to detect the sensitivity and specificity of RT-RAA.【 Results 】The results showed that the proposed method had no cross-reactivity with the nucleic acids of swine fever virus (CSFV), pseudorabies virus (PRV Bartha-K61), porcine epidemic diarrhea virus (PEDV Purdue) and porcine infectious gastroenteritis virus (TGEV LJX). The minimum detection limit of this method was 1.71×10¹ copies/μL for highly pathogenic strains and 2.19×10³ copies/μL for classical strains. Compared with the PCR method, the sensitivity and specificity of RT-RAA fluorescence quantification method were 95.5% and 100%, respectively. The sensitivity and specificity of RT-RAA classical strain fluorescence quantification method were 93.0% and 100%, respectively and the two methods were highly consistent. 【 Conclusion 】The PRRSV RT-RAA fluorescence method established in this study can distinguish two different strains with good specificity and high sensitivity.