Abstract: Porcine reproductive and respiratory syndrome virus (PRRSV) poses a serious threat to the healthy development of the global swine industry. The virus is of extensive genetic heterogeneity, with successive emergence of divergent lineages in China—including GM2-like, NADC30-like and NADC34-like strains, following the initial outbreak of highly pathogenic PRRSV. The concurrent circulation of multiple lineage strains has facilitated frequent viral recombination events. Several recombinant variants exhibit expanded cellular tropism and heightened virulence in pigs. Moreover, recombination-driven antigenic variation can compromise diagnostic specificity and diminish vaccine-induced immunity. Consequently, recombinant PRRSV strains have emerged as a critical challenge in disease surveillance, diagnosis, and control. This review synthesized recent research on PRRSV recombination, with emphasis on the genomic architecture, spatiotemporal distribution, and molecular determinants of recombination events; their phenotypic consequences, including impacts on viral fitness, host range, pathogenicity and current hypotheses regarding underlying recombination mechanisms. By consolidating these advances, this review aimed to inform strategies for mitigating recombination risk, elucidate fundamental molecular pathways governing recombination, accelerate the development of broadly protective vaccines, and enable precision interventions for PRRS management.