Disclosed are a fluid pumping device and a horizontal compressor. The fluid pumping device comprises a pump structure in the form of an internal-meshing gear pump and is provided with first and second pump members, a pump housing structure for accommodating the pump structure, and at least two suction paths and/or at least two discharge paths. Suction and compression cavities are defined between the first and second pump members; the at least two suction paths are configured to rotate with the pump structure, and a fluid can be sucked into the suction cavity via the at least two suction paths respectively; and the at least two discharge paths are configured to rotate with the pump structure, and the compressed fluid can be discharged from the fluid pumping device via the discharge paths respectively. The fluid pumping device is assembled in the horizontal compressor.