The invention discloses a device for continuously separating negative and positive ions from a solution and an application method of the device. The device comprises a central cylindrical membrane electrode, an arc-shaped counter electrode, a cylindrical insulating shell, a motor control device, an external power supply and a flexible contact type sealing unit, wherein the central cylindrical membrane electrode has an electric control ion exchange function; the flexible contact type sealing unit is used for uniformly distributing an annular chamber between the central membrane electrode and the external arc-shaped counter electrode into a raw material liquid chamber and a regenerated liquid chamber; raw material liquid and regenerated liquid are injected to the raw material liquid chamber and the regenerated liquid chamber respectively; different potentials are applied to the central membrane electrode and the external arc-shaped counter electrode respectively, and adsorption of the membrane electrode on target ions in the raw material liquid and desorption of the membrane electrode in the regenerated liquid can be continuously finished. According to the device disclosed by the invention, a liquid patch does not need to switched, the sealing effect is good and the operation is convenient; the ions in the solution are directly adsorbed/desorbed on the surface of the membrane electrode; the ion transferring speed is rapid and the ion separation efficiency is high; the membrane electrode can be operated continuously.