The invention provides a method for quickly and synchronously detecting rice stripe virus (RSV) and rice black-streaked dwarf virus (RBSDV) in an insect vector laodelphax striatellus, and belongs to the field of plant protection. According to nucleotide sequences of the rice stripe virus RNA4 and the rice black-streaked dwarf virus S2, three primers are designed as follows: [A] RS-F, [B] RB-F, and [C] RSRB-R, wherein A and C are combined to detect the rice stripe virus; the B and C are combined to detect the rice black-streaked dwarf virus. After extracting total RNA of single laodelphax striatellus, only one RT-PCR is needed, so that the rice stripe virus and the rice black-streaked dwarf virus can be detected, and thus, and quick and synchronous detection for the two viruses in the laodelphax striatellus is realized. Compared with the conventional method for detecting one virus by virtue of one RT-PCR, the cost is greatly saved and the time is saved, and thus, the method is a quick, simple, flexible and specific detecting method. The method disclosed by the invention can be applied to monitoring work of a virus carried rate of a field laodelphax striatellus colony, and can also be applied to related research work of a virus and vector interaction mechanism.