The plasticized polyvinyl chloride (PVC) gel-based soft actuator exhibits a fast response in air, large deformation, and low power consumption under an electrical field, so it shows great potential for use as a new type of soft actuator. In our previous study, we have developed a multilayered expansion and contraction-type actuator using PVC gel and stainless mesh electrodes. However, the actuator using rigid metal electrodes bring challenges of a notable weight and size, a limitation in flexibility and performance. In this study, to develop an actuator with higher performance and flexibility, we proposed a novel sheet actuator using PVC gel and flexible electrodes. We explain the driving mechanism of the proposed sheet actuator and investigate the basic characteristics of the actuators with different content of plasticizer and membrane thickness. Besides, we conducted a comparison experiment between the proposed PVC gel sheet actuator and the traditional dielectric elastomer actuator, founding that, the PVC gel sheet actuator had a positive potential to be driven at a lower DC field to get a bigger deformation and a faster response than those of the traditional dielectric elastomer actuator. And we discussed the difference between the two types of actuators with a theoretical model, finding a good agreement with the experimental results.