PVA film is fully degradable， but it is weak in water resistance. In this study， nano-TiO2， acetic acid， urea and MgCl2 were added to PVA to improve the film property of water resistance. The mechanical， thermodynamics， microstructure and antibacterial properties of the films were investigated. It was found that the water resistance of the film had been greatly enhanced. The dissolution rate of the PVA-TiO2-MgCl2 film decreased about 73.32% compared to the PVA film， and the contact angle increased about 51.49%. The microstructure was observed by SEM and AFM， and found that the nanoparticles were evenly dispersed in the film. The bacteriostatic rate of the Mg2+ modified film for Escherichia coli and Staphylococcus aureus at the 24 h reached 34.98%， and 39.90%， respectively.