A new pyrrolidonium ionic liquid ([DMPy]OH) was synthesized with 1-Methylpyrrolidine via two-step procedure. Additionally, [DMPy]OH and nano-TiO2 were introduced into the polyvinyl alcohol (PVA) as matrix by physical doping, and then glutaraldehyde (GA) was used to cross-link PVA to obtain PVA-[ DMPy] [OH]-TiO2 composite membrane. The self-assembly effect of non-coordinating Ti4+, O2- on the surface of Nano-TiO2 and anion-cation in [DMPy]OH, and the semi-interpenetrating structure formed by GA cross-linked PVA can reduce the loss rate of ionic liquid in the membrane and increase the number of \"cationic active site\", speed up OH- migration rate, increase anionic conductivity. The existence of self-assembly between Nano-TiO2 and [DMPy]OH was confirmed by X-ray diffraction (XRD) and Mapping. The mechanical properties, thermal stability, conductivity, alkali resistance, and other properties of the composite membrane were also tested. The result indicates that PVA-[DMPy]OH]-TiO2 composite membrane has uniform morphology, the introduction of Nano-TiO2 can reduce the loss rate of IL, enhance the conductivity and mechanical properties. The experiment results show that when the [DMPy]OH mass fraction were 25wt% and Nano-TiO2 were 1wt%, the conductivity is 2.78×10-3 S.cm-1 at 80℃, the ionic liquid loss rate is 23.2% at room temperature, conductivity was 19.4% higher than that without Nana-TiO2 addition, and the loss rate of ionic liquid was also greatly decreased (about 34.3%). No obvious variety in conductivity is observed for the composite membrane after immersing in 3M KOH solution at room temperature, show that membrane has excellent alkali stability. TGA shows that membrane has good thermal stability; the initiate decomposition temperature is higher than 200oC.