The utility model discloses a horizontal type double-wall fan coil which comprises a machine set main body, wherein the machine set main body comprises a heat exchanger, a filtering net frame is fixed on the machine set main body, and the two ends of the machine set main body are provided with side boards; a horizontal board is arranged under the heat exchanger, and a water collecting disc is arranged under the horizontal board; the inner surfaces and the outer surfaces of a copper pipe, a collecting pipe and a liquid outlet pipe of the heat exchanger are plated with a plurality of copper layers; each side board comprise an outer board, an inner board and a middle board, wherein the middle board is a plastic foaming board; the filtering net frame is provided with an strengthening pull rod; and a wire inlet hole of each side board is provided with a plastic IP54 connecting box with a good protecting effect. The inner surfaces and the outer surfaces of the copper pipe, the collecting pipe and the liquid outlet pipe of the heat exchanger are plated with the copper, each side board consists of the outer board and inner board which are made from the metal and the middle board which is made from the plastic foaming board, and the horizontal board is arranged under the heat exchanger for baffling the water and the like, so that the horizontal type double-wall fan coil has the functions of being anti-cold, antifreezing, soundproof, heat-preserving, dustproof and waterproof, is more convenient to install and disassemble, and is higher in bearing capability.