In this paper, PVA was modified by mixture of plasticizer with glycerol and caprolactam. DSC and FTIR were used to test the thermoplastics formability of modified PVA. The results showed that the melt temperature of modified PVA with plasticizer was decreased significantly. With the same content of mixture of plasticizer (20%), the melt temperature of modified PVA is 207°C when the mass ratio of glycerol and caprolactam is 3:2. Under the same content of plasticizer, plasticized effect of mixture of plasticizer was enhanced more than the plasticizer of glycerine or caprolactam alone, so the melt temperature of modified PVA with mixture of plasticizer was lowest relatively.