The invention discloses primers for identifying an avian infectious bronchitis virus strain type, an RT-PCR detection kit, a method and application. Sequences of the primers are as follows: an H120 forward primer: 5'-ATTGCTTACGGTCCTCT-3', and an H120 reverse primer: 5'-CTGCTGGTTGACATCTT-3'; a QX forward primer: 5'-GTACAGGGTCTTGTCCTA-3', and a QX reverse primer: 5'-GTGTTGCTTAATTCACCT-3'; an LDT3 forward primer: 5'-CGCCACAGCAGGAAGAAT-3', and an LDT3 reverse primer: 5'-GTCCGTAGTTGGAATGAAGA-3'; a 4/91 forward primer: 5'-CCAGATAGGCGGTGTTAG-3', and a 4/91 reverse primer: 5'-TCGGCAATAGGAAAGTGT-3'. The primers, the RT-PCR detection kit, the method and the application have the beneficial effects that the kit provided by the invention separately amplifies four fragments of different sizes by only once gradient RT-PCR, and then, vaccine strains and popular wild strains of infectious bronchitis of chickens can be rapidly identified and diagnosed; the kit has the characteristics of high efficiency,low cost, high specificity, high sensitivity and the like; a convenient and quick detection method is provided for the differential diagnosis and molecular epidemiological analysis of avian infectious bronchitis viruses and prevention and control of the avian infectious bronchitis viruses.