In order to investigate the epidemiological characteristics of porcine reproductive and respiratory syndrome virus（PRRSV）in intensive swine farms，a total of 3 324 samples were collected in 2021 from pigs suspected to be infected with PRRSV and all boars in 7 intensive farms in Hubei Province for pathogenic detection by triple-nested RT-PCR to analyze the prevalent situation in different breeding types，growth stages，seasons and strains，followed by sequencing and genetic evolution of positive products. The results showed that 323 positive samples were detected，with the positive rate of 9.72%（323/3 324）；the lowest positive detection rate was 2.66%（20/752）in breeding farms，similar in commercial propagation farms and fattening farms，which were 11.82%（169/1 430）and 11.73%（134/1 142）respectively；highest in nursery pigs（17.23%），followed by growing finishing pigs，suckling piglets and sows，with 11.30%（121/1 071），5.26%（30/570）and 3.24%（20/618）respectively，no PRRSV infection was found in breeding boars；PRRSV could be prevalent throughout a year，and the positive detection rates in spring，summer，autumn and winter were 18.16%（148/815），6.94%（60/864），6.10%（34/557）and 7.44%（81/1 088）respectively；that in spring was significantly higher than those in other seasons（P＜0.05），but with slightly difference in summer，autumn and winter（P≥0.05）；all three types of strains including NADC30-like strain，classical strain and highly pathogenic variant strain were prevalent，accounting for 49.54%，21.36% and 29.10%，respectively，the proportion of NADC30-like strain was significantly higher than other types of strains（P＜0.05）. In conclusion，PRRSV was widely prevalent in the 7 farms，especially in commercial propagation farms and fattening farms；the risk of PRRSV infection was high in nursery pigs，lower in breeding boars；and NADC30 like strain was the dominant epidemic strain，especially in spring. Therefore，immunization and monitoring should be strengthened by the farms according to the prevalent characteristics of PRRSV，and targeted measures for prevention and control should be developed.