In response to China′s "antibiotic-free" policy,plant extracts have emerged as a prominent area of research in the field of animal husbandry,particularly as feed additives.These extracts,which are derived from natural sources,exhibit a wide variety of types and functional properties.As feed additives,plant extracts have been shown to enhance immune function,alleviate stress,exhibit antioxidant effects,regulate gut microbiota,and possess antimicrobial and anticancer activities.Current research on immune modulation in animals has predominantly focused on plant polysaccharides, flavonoids and polyphenols.However,due to the complexity and diversity of their chemical components and structures,the biological effects of these plant extracts on animals can vary considerably.This paper provides a comprehensive review of the immunomodulatory effects of plant extracts on animal immune function,critically analyzes the existing research gaps,and offers scientific evidence and theoretical insights to support the further development,application,and promotion of plant extracts as feed additives.