The invention belongs to the technical field of machinery, and relates to a rotary heat exchanger, in particular to a rotary tube bundle heat exchanger, which comprises a shell, a left tube plate, a right tube plate, a tube nest bundle, a motor, a rotating pipeline a, a rotating pipeline b, a bearing a and a bearing b. A fluid inlet and a fluid outlet are arranged at the upper end and the lower end of the shell respectively, through holes are arranged at the left end and the right end of the shell, annular grooves are arranged on the through holes, the left tube plate and the right tube plate are hemispherical, and the axis of the tube nest bundle is parallel to that of the shell. As the heat exchange coefficient of the rotary tube bundle heat exchanger is obtained without increasing the flow velocity of media, both a heat exchange medium a in an inner cylinder and a heat exchange medium b between the inner cylinder and an outer cylinder can enter the heat exchanger at a low speed, fluid resistance is greatly reduced, power needed for conveying fluids is remarkably decreased, and energy is saved.