A peptide nucleic acid of subgroup J avian leukosis virus and uses of the same are provided. The sequence of the peptide nucleic acid is one or more selected from the following sequences: sequence 1: 5′AGACUAAGGCAAAAAUCUGUU-3′ sequence 2: 5′-ACGACUUAUUGAAAAACUCUC-3′ sequence 3: 5′-UAUAACCGUCUGUAGUUGGAC-3′ sequence 4: 5′-ACAUAUUUGAUUAUCUCUCCU-3′. The peptide nucleic acid, disclosed in the present invention, can specifically and directly inhibit PRRSV replication, has good antiviral effect and no drug residues, without any toxic side effect and drug resistance.