The invention discloses a device and a method for determining water absorption of a silicone rubber material under the action of an electric field, relates to the technical field of grids and can determine the influence of the electric field on water absorption and moisture absorption of the silicone rubber material. The device for determining water absorption of the silicone rubber material under the action of the electric field comprises a container for containing an aqueous solution, wherein a first electrode is arranged in the aqueous solution in the container, a second electrode is arranged below the container, a silicone rubber sample is clamped between the second electrode and the container, a first opening is formed in the lower part of the container, the outer edge of the first opening is located in the outer edge of the silicone rubber sample, and the first electrode and the second electrode are used for applying the electric field to the silicone rubber sample. The device is used for determining the water absorption of the material.