This article proposes a reinforced soft gripper with a mechanically strengthened electroadhesion pad and a multilayered dielectric elastomer (DE) actuator, for practical robotic application. The reinforcement of the electroadhesion pad is achieved by a metallic electrode pattern printed on a flexible polyimide film, which has a higher elastic modulus than typical soft materials. Moreover, the multilayered DE actuator is used to increase the bending force of the soft gripper. We maximize the gripper performance by optimizing design factors of the electroadhesion and multilayered DE through experimental and simulation analysis. In this study, we demonstrate dynamic picking up and placing tasks with the designed gripper assembled to a robotic manipulator. The gripper can lift and move various shaped objects 100 times heavier than the gripper's mass of 6.2 g. Moreover, the soft gripper with a large area can firmly hold 16.8 kg, with optimized specifications.