A membrane separation apparatus includes: a shell, wherein an inner surface of the shell is an arc surface, and at least one medium inlet and at least one medium outlet used for discharging a medium that is separated are arranged on the shell; a rotor arranged inside the shell, wherein at least two contact ends that are always in slidably contact with the inner surface of the shell are arranged on an outer surface of the rotor, the outer surface of the rotor and the inner surface of the shell form sealed separate cavities between the adjacent contact ends, and an empty part inside the rotor is used as a medium storage chamber; and separation chambers arranged inside the rotor.