The invention relates to a virus isolate for infectious bronchitis and application in vaccine preparation. The virus isolate is named as an isolate cb2, and has been collected into Common Microorganism Center of China Committee for Culture Collection of Microorganisms on June 21st, 2016; the microorganism collection number is CGMCC No.12657. The virus isolate has the advantages that the isolated strong-poisonous virus isolate for the infectious bronchitis is used for the adaptive domestication on chick embryos, so as to obtain the virus isolate with high titer for the growth of the chick embryos; a stable disease occurrence model can be established, the good specificity and immunogenicity of the virus isolate are maintained, and the virus isolate can be used for the production and preparation of vaccines; after the virus isolate is deactivated, the virus isolate is prepared into a deactivating vaccine to perform evaluation and testing on the immune effect and safety; proofed by results, the vaccine is safe to the targeted animal, the adverse effect of local and whole body due to vaccines is avoided, and the infection caused by kidney and respiration type infectious bronchitis viruses can be effectively prevented.