The reflection band gap of cholesteric liquid crystal (CLC) is usually between 50 and 100 nm. To enhance the usefulness of CLC, the external stimulation can be applied to broaden the reflection bad gap. The polymer network can be moved by the action of direct current voltage in polymer-stabilized cholesteric liquid crystal (PSCLC) with negative dielectric anisotropy, results in broadening the reflection band gap, which is usually driven by a large voltage. In this paper, the influence of polymer monomer’s concentration, cell thickness of liquid crystal, and ultraviolet absorption dye on the reflection band was studied. The reflection band of PSCLC is broadened by 3 times, and the required driving voltage is lowered to 7.5 V. After the driving voltage is removed, PSCLC system quickly returns to the original optical performance, shows the good reversible change.