Membrane distiller

The invention discloses a membrane distiller belonging to the technical field of a membrane separation device. The membrane distiller comprises a rectangular shell, upper and lower cover plates connected with the shell, hollow fiber membrane module units arranged in the shell, hollow pipe module units and separation nets placed between the hollow fiber membrane module units and the hollow pipe module units, wherein the cover plate is provided with a liquid material inlet/outlet; a shell cavity is divided into three sections; upper and lower cavities are of symmetrical double-cavity structures; a same-side cavity of the upper and lower cavities is fixedly provided with at least two rows of the hollow fiber membrane module units by an adhesive; the other same-side cavity of the upper and lower cavities is fixedly provided with at least two rows of the hollow pipe module units by the adhesive; the upper and lower cavities are respectively provided with separation plates in the same direction; and a communicated