The invention provides a horizontal-type fixed bed reactor which is used for producing propylene with oxygen-containing compound as the raw material. The reactor comprises a casing, a raw material inlet is arranged at one transverse end of the casing, a product outlet is arranged at the other end, a porous separating part is arranged inside the casing, and separates the internal space of the casing into at least four transverse areas, two of the areas which are positioned at the ends of the casing are respectively communicated with the raw material inlet and the product outlet, and other areas are a reaction area and a cooling area which are arranged at intervals; a cooling fluid inlet is arranged on the casing corresponding to the cooling area. The horizontal-type fixed bed reactor has the advantages that the structure is simple, the design, the manufacture and the maintenance of the equipment are easy, the operation is convenient, the reaction is easy to control, and good reaction condition is easy to maintain.