The invention discloses a heat preservation single-screw pump. The two ends of a pump case of the pump are connected with a left cover plate and a right cover plate respectively, the two sides of the pump case are provided with a heat conducting oil inlet and a heat conducting oil outlet respectively, the right cover plate is externally connected with a sealing cover, and gaskets are arranged between the left cover plate and the pump case and between the right cover plate and the pump case. A screw is arranged in the pump case of the pump, a gear is connected with the screw in a matched mode, a pump sleeve and a bearing seat are sequentially arranged between the screw and the pump case, a bearing is arranged between the screw and the right cover plate, and a mechanical seal is arranged between the screw and the sealing cover. An electric heating bar is arranged in the left cover plate, and an oil drainage bolt is arranged on one side of the left cover plate. The single-screw pump is good in heat preservation effect, and therefore it is guaranteed that a medium cannot solidify or cake at low temperature, it is guaranteed that no oil leaks out of a transmission shaft, and in addition, the use power of the pump is very low.