The new progress of polymer-dispersed liquid crystals technology is introduced, and the enhanced scattering of liquid crystal micro-droplets is studied by optical principle. The criterion is proposed for both the optimum distance and the optimum diameter of liquid crystal micro-droplets, respectively. Using the two criteria, the condition of reflection increasing film for the optical thickness of polymer located at the spacing of the adjacent liquid crystal micro-droplets, and the condition of birefringence destructive interference for the diameter of liquid crystal micro-droplets are satisfied. The method of calculating the optimum mixture ratio of polymer and liquid crystal is proposed, and the results are given according to the space filling efficiency of atomic packed in crystallology. With an ideal model of enhanced scattering of polymer-dispersed liquid crystals, the anomalous scattering computation and experimental results for the liquid crystal micro-droplets diameter, and the mixture ratio of polymer and liquid crystal are explained theoretically in the simple and clear ways.