The invention discloses a multistage demister. The multistage demister comprises a plurality of demisting components; each demisting component comprises a gas riser pipe and an outer barrel; the outerbarrel is arranged on the outer side of the gas riser pipe and located on the same axis as the gas riser pipe; the inner surface of the outer barrel is of a thread structure; the gas riser pipe is fixed on a tray; the top of the gas riser pipe is provided with a sealing cover; a rectifying passage is arranged on the circumference of the gas riser pipe; and the inner wall of the outer barrel is provided with internal threads. The demister of the invention realizes the separation of droplets from gas by rectification, acceleration and scraping effect in the flowing process of fluids. The demister of the invention has the advantages of simple structure, convenient installation and small possibility of scale formation, and can effectively realize gas-liquid separation and reduce entrainment of mist.