Porcine circovirus type 2 (PCV2) is the main pathogen causing postweaning multisystemic wasting syndrome, which leads to enormous losses for porcine industry. However, the regulatory mechanism of PCV2 replication in host cells remains not been clarified. Here, pig DNMT3B was identified as be a host regulator associated with PCV2 infection via RNA-seq analysis. We demonstrated that upregulation of DNMT3B expression can effectively inhibit PCV2 replication in PK15 cells. Besides, TMEM37 acts as a key downstream target of DNMT3B in PCV2-infected PK15 cells. TMEM37 knockdown significantly slowed Ca