The invention discloses a multi-PCR (Polymerase Chain Reaction) primer group for detecting A, B, J and K subgroups avian leukosis viruses (ALV). The multi-PCR primer group comprises a common upstreamprimer SEQ ID NO. 1 for detecting the avian leukosis virus, a downstream primer SEQ ID NO. 2 of the A subgroup avian leukosis virus, a downstream primer SEQ ID NO. 3 of the B subgroup avian leukosis virus, a downstream primer SEQ ID NO. 4 of the K subgroup avian leukosis virus and a downstream primer SEQ ID NO. 5 of the K subgroup avian leukosis virus. The invention further discloses a multi-PCR kit for detecting the A, B, J and K subgroups avian leukosis viruses; the multi-PCR kit comprises the multi-PCR primer group provided by the invention, Premix Ex Taq DNA (Deoxyribonucleic Acid) polymerase, sterile double distilled water and a negative and positive control plasmid DNA template. Furthermore, the invention further discloses a multi-PCR method for detecting the A, B, J and K subgroupsavian leukosis viruses. An experiment shows that the multi-PCR primer group provided by the invention can be used for detecting the A, B, J and K subgroups avian leukosis viruses from a sample at thesame time, has the advantages of strong specificity, high sensitivity and convenience for operation and result judgment and is suitable for detecting batch samples and primary identification of exogenous ALV.