Fuente: WIPO "tobacco agriculture" The invention discloses a method for detecting three viruses such as tobacco mosaic virus, cucumber mosaic virus and tobacco vein banding mosaic virus in tobacco mosaic plants. Viruses in a sickness sample are trapped through specific hybrid antibodies of the tobacco mosaic virus, cucumber mosaic virus and tobacco vein banding mosaic virus, the total RNA of the sample is not needed to be extracted for performing random primer reverse transcription and specific virus composite PCR (Polymerase Chain Reaction), and a method for simultaneously detecting 1, 2 or 3 different viruses in the three viruses in a single tube is established for specially aiming at the conditions that the upper leaves in tobacco are severely damaged and pathogens cannot be distinguished from the symptoms in the tobacco production process. The detection time is only 5 hours. The method comprises the following steps: combining rapid and specific immunoprecipitation and sensitive composite RT-PCR, setting cDNA products of healthy tobacco random primers and positive plasmids of corresponding virus PCR specific fragments as negative and positive control, and rapidly, accurately and sensitively detecting field tobacco plant samples, antiviral materials and field environment suspected infection sources.