In order to better study the polymer stabilized blue phase liquid crystal devices, considering the difference of dielectric constant between polymer and blue phase liquid crystal and the change of electric field, we established a theoretical model suitable for polymer stabilized blue phase liquid crystal display. Firstly, we calculated the simulation result to fit the experiment results of blue phase liquid crystal displays with two group of polymer ratio, and obtained the saturation birefringence of blue phase liquid crystal close to the birefringence of liquid crystal. Then, we studied the influence of dielectric constant and content of polymer monomer on driving voltage. Finally, we calculated the influence of electrode width and gap on the operating voltage and transmittance of polymer stabilized blue phase liquid crystals devices driven by in-plane electric field, and obtained the device structure with high transmittance and low operating voltage. With the increasing dielectric constant of the non-liquid crystal material, the operating voltage is decreased, and the greater the content, the greater the operating voltage decreased. For the non-liquid crystal material content of the general blue liquid crystal being about 10%, the operating voltage can reduced from 97 V（εP=3）to 55 V（εP=30), the change of the maximum transmittance is very small, even can be ignored. In addition, the different dielectric constant of non-liquid crystal materials only affect the operating voltage, and has a little effect on the maximum transmittance and the shape of electro-optic curve. The results have important guiding significance for optimizing the material composition of polymer stabilized blue phase liquid crystal and improving polymer stabilized blue phase liquid crystal devices.