Solidification mechanism of PVA release film, factors affecting this process and the role of each component were introduced, effects on the film's apparent quality and performance of different content of each component were presented. Experimental results show that the optimal preparation conditions of PVA slow-release membrane are 30 microns for the thickness, 2.0% volume fraction for glycerin, 11% ~ 17% mass fraction for PVA, 1% ~ 2% mass fraction for SDS.