The invention discloses a mucous membrane detacher. The mucous membrane detacher comprises an external sleeve assembly, an electric coil, a sliding ring and a pulling rope; part of the electric coil is equipped with an insulation layer, and the rest parts are exposed for detaching a mucous membrane; the sliding ring is arranged on the external sleeve assembly and can axially move relative to the external sleeve assembly; an electrode plug is arranged on the sliding ring; the pulling rope is axially moved to be inserted into the external sleeve assembly; one end of the pulling rope is connected with the electric ring and while the other end of the pulling rope is electrically connected with the electrode plug on the sliding ring. With the adoption of the mucous membrane detacher, tissue can be closed conveniently when detaching the tissue below the mucous membrane; the positioning is accurate; therefore, the operation is convenient and fast; the difficulty of doctors at operation is greatly reduced, and thus the time can be saved; the phenomenon of burning out other good tissues can be avoided.