African swine fever virus K421R gene and replication-deficient African swine fever vaccine prepared by using same

The invention discloses an African swine fever virus K421R gene and a replication-defective African swine fever vaccine prepared by using the same, and belongs to the field of biological medicines. The technical problem to be solved by the invention is how to safely and effectively prevent African swine fever. In order to solve the problem, the invention provides the replication-deficient African swine fever vaccine, the vaccine comprises a replication-deficient African swine fever virus, a coding gene of a protein pK421R is deleted from the genome of the virus, or the function of the coding gene of the protein pK421R in the genome of the virus is inactivated, and the amino acid sequence of the protein pK421R is SEQ ID No.2. The key essential gene K421R for controlling ASFV replication is found, and after a pig is immunized with the gene deletion replication-deficient virus, the immunized pig can obtain 100% challenge protection by attacking with ASFV virulent virus. The gene deletion virus can be used as a r