Objective:　The　pollution　of　plastic　food　packaging　is　a　worldwide　environmental　problem.　In　this　study,　photocatalytic　technology　was　used　to　prepare　for　food　packaging　film　which　soy　protein　isolate　was　as　a　raw　material,　expect　the　effective　inactivation　of　harmful　microorganisms　by　photocatalysis,　in　the　purpose　of　improve　food　quality,　extend　shelf　life　as　well　as　saving　packaging　materials.　Method:　Through　single　factor　experiments　and　orthogonal　test　to　optimize　the　casting　process.　Water　vapor　permeability,　air　permeability　and　transmittance　were　used　as　indicators　of　the　physical　properties　of　films.　On　the　basis,　effects　of　TiO2,　irradiation　time　and　wavelength　on　antibacterial　properties　of　composite　film　were　investigated.　Result:　The　optimum　condition　for　making　composite　film　include　4.50　g　of　SPI,　2.00　g　of　titanium　dioxide,　3.75　g　of　glycerol　in　150　mL　solution　which　water　vapor　permeability　was　5.19　gmm/(m2·d)　kpa,　transmittance　was　71.60%,　oxygen　permeability　was　0.12　mg/(cm2d),　carbon　dioxide　permeability　was　11.82　mg/(cm2·d),　intensity　of　tension　was　0.49　MPa,　elongation　at　break　was　98.96%.　When　exposed　to　two　hours　irradiation　of　UV　light　at　365　nm,　the　bactericidal　activity　of　SPI　films　containing　TiO2　nanoparticles　(2.00　g/150　mL)　against　gram　negative　Es-cherichia　coli　(E.　coli)　and　gram　positive　Staphylococcus　aureus　(S.　aureus)　can　reach　71.01%　and　88.49%,　respectively.　Conclusion:　With　better　physical　properties　and　strong　antibacterial　activity,　the　film　incorporation　of　TiO2　nanoparticles　has　the　potential　to　replace　synthetic　plastics.