The highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV) has caused huge economic losses to the pig industry in China. This study evaluated the damage to peripheral immune tissues in the early infection of HP-PRRSV, including the hilar lymph nodes, mandibulares lymph nodes, inguinales superficials lymph nodes, spleens, and tonsils. HP-PRRSV infection led to a reduction in CD4 and CD8 T cells, as well as CD19 B cells, in the tonsils. Additionally, CD163 macrophages and CD56 NK cells increased in all peripheral lymphoid organs, with NK cells migrating toward the lymphoid follicles. However, no significant changes were observed in CD11c dendritic cells. RNA-seq analysis showed the down-regulation of T and B cell functions, while macrophage and NK cell functions were enhanced. Gene Ontology (GO) and KEGG pathway analysis indicated the up-regulation of necroptosis processes. Western blotting and immunofluorescence confirmed that HP-PRRSV induced PKR-mediated necroptosis in immunocytes. This study provides new insights into the effects of early HP-PRRSV infection on peripheral immune organs, highlighting dynamic shifts in immune cell populations, virus-induced immunosuppression, and the role of PKR-mediated necroptosis. These findings improve our understanding of the immunomodulation induced by PRRSV infection.