The utility model discloses a split type horizontal air-cooled radiator, which comprises a chassis. At least two serially connected horizontal air-cooled radiator monomers are arranged on the chassis. The split type horizontal air-cooled radiator adopting a split type assembly structure is convenient in construction and installation and flexible in installation position, which can fully utilizes the space of a platform. Due to the arrangement of the air-cooled radiator monomers, the amount of adopted pipelines is reduced and the installation space is reduced. Since the forced air-cooled cooling mode is adopted by the radiator, the pipeline corrosion caused by the cooling of seawater is avoided and the service life of the radiator system is prolonged so as to save the operation cost of equipment. Due to the arrangement of the split type assembly structure, when a single radiator is damaged, the radiator can be repaired separately without the need of shutdown maintenance. Therefore, the unit operation will not be seriously influenced by the damaged radiator and the down time is reduced. Meanwhile, the equipment operation rate is improved and the normal production of the platform is not affected. As a result, the economic benefit is increased.