PVF film prepared by means of extruding casting was cooled in water bath at different temperature,the crystallinity of the film sample was tested by XRD,the desolvation of the PVF film was made at different given temperature and got the curves of the desolvation rate.The results showed the higher the cooling temperature of water bath,the higher the initial crystallinity would be; the lower the initial crystallinity of film,the faster the desolvation rate would be; the crystallinity of film would increase during the desolvation,and the increase of the crystallinity would decrease the desolvation rate simultaneous.