In order to improve hydrophilicity and mechanical properties of polyvinylidene fluoride (PVDF) membrane, silane coupling agent silane ethenyltrimethoxy and alkali were respectively used to modifie Al2O3 and PVDF, with benzoyl peroxide (BPO) as initiator, the modified Al2O3 was introduced into PVDF, the modified Al2O3 / PVDF hybrid membrane was prepared through thermal induced phase transition as well. Subsequently, the effects of silane coupling agent on Al2O3 particle size were investigated, and the effect of different alkali concentration and alkali treatment time on PVDF structure were studied. Additionally, the properties of modified membrane were studied as well. As the results, when the mass fraction of silane coupling agent was 33%, the size of Al2O3 particles reduced to 43.47 nm. Accordingly, when the mass fraction of modified Al2O3 particles was 5%, rejection and flux of the hybrid membrane reached up to 83.12% and 621.5 L/m2.h respectively, and the mechanical properties of hybrid membrane reached up to 5.01Mpa.The higher flux and mechanical properties of the membrane are attributed to the introduction of modified Al2O3 particles.