The effects of nano-particles (CaCO3, SiO2 and organic modified montmorillonite (OMMT) on the suppression of DOP migration from PVC matrix and mechanical properties of PVC composites were evaluated. The results indicated that the three kinds of nano-particles could improve the ability of anti-migration of DOP in flexible PVC. A certain content of nano-particle could decrease the migration rate of DOP. The addition of 5 phr SiO2 decreased the extraction rate of DOP to 15.6%, and SiO2-5/PVC composite film possessed superior anti-extraction property. The introduction of 5 phr OMMT reduced the volatilization of DOP to 0.067%, and OMMT-5/PVC exhibited the lowest volatilization of DOP. Inorganic nano-particles with high surface energy were easy to aggregate, and the influences of aggregation on the properties of composites were clearly detrimental, which results in a drastic decrease of polymer anti-migration and mechanical performance.