Proanthocyanidins (PC) with high anti-oxidative activity are broad categories of polyphenol compounds that widely exist in plants and are widely used in food, medicine and other fields. However, PC has low bioavailability due to its poor stability, and improving its stability will help expand its application range.A kind of monodisperse mesoporous silica nanoparticles (MSNs) was prepared by aerosol method using tetraethoxysilane (TEOS) as silica precursor and cetyl and trimethyl ammonium bromide (CTAB) as template. PC was subsequently loaded into MSNs to prepare PC-MSNs complexes using dipping method, and the loading effects of temperature, PC mass fraction, processing time, and MSNs addition amount were examined. The release of PC-MSNs was studied by simulating the gastrointestinal tract (GIT) conditions. The results showed that the most suitable conditions were as follows:MSNs addition amount was 5mg/mL, PC mass fraction was 4mg/mL, and the alternating treatment program of variable temperature was 30℃ for 0.5h, then 4℃ for 0.5h and repeated this process twice. In this condition, the loading mass was highest, and MSNs loading capacity was 512mg/g.According to Brunauer-Emmett-Teller (BET) analysis method, specific surface area and pore volume were decreased significantly, indicating that PC was successfully loaded into MSNs particles.Unloaded PC only retained 50.2% at the end of intestinal digestion, while loading PC on MSNs system could prevent it from damage by gastric acid and successfully arrived in small intestine. There was 77.1% PC retained at the end of intestinal digestion, indicating that MSNs could significantly increase the PC mass in small intestinal juice and improve its bioavailability.