When ac voltage is applied, the refractive indexes of liquid crystal droplets and polymer binders match gradually, and the phase-type electrical-controlled switchable focus lens based on polymer dispersed liquid crystal (PDLC) material is switched on and off . In experiments, recipes and characteristics of micrometer size and nano-scale size polymer dispersed liquid crystal materials have been researched. The newly developed optimized nano-scale liquid crystal droplets polymer dispersed liquid crystal recipe is adopted to fabricate polymer dispersed liquid crystal cell samples with thickness of 5～6 μm. And in plane wave and spherical wave interference optical recording system, primary off-axis polymer dispersed liquid crystal focus-switchable holographic lens sample is developed with focal length of 20 mm. Amplified images with positive one-order diffraction are achieved and the driving voltage threshold for “0”, “1” transfer is about 60 V ac voltage. Furthermore, the conception of electrical-controlled focus-switchable optical image system based on polymer dispersed liquid crystal focus-switchable lens integration is put forward.