DDM-BSA composite nanomaterial was synthesized by using BSA,2,4-dihydroxyphenyl,2,6-dimethylphenyl and methanone (DDM) (loaded drug) as raw materials through desolvation method. The prepared composite nanomaterial was characterized by ultraviolet-visible (UV-vis) spectrometer,transmission electron microscope (TEM),laser particle size analyzer et al. The results showed that the composite nanoparticles were uniformly dispersed with an average particle size of 49.3 nm. A loading rate of 37.4% for DDM drugs was obtained and in vitro release rate was calculated to be 95.4% after 80 h. On this basis,the effects of composite nanoparticles on the proliferation of porcine reproductive and respiratory syndrome virus (PRRSV) were evaluated. The results showed that when the mass concentration of bovine serum albumin-loaded DDM was 12 μg/mL,the survival rate of the MARC-145 cells was more than 90%,and the PRRSV virus proliferation was inhibited,indicating better antiviral effect than that of DDM.