Provided is an adsorptive hybrid desiccant cooling system, including a desiccant cooler comprising a housing including a regeneration passage and a dehumidification passage, a desiccant rotor mounted on a partition wall dividing the regeneration passage and the dehumidification passage from each other, a regeneration preheater installed upstream of the desiccant rotor in the dehumidification passage, and a cooler installed downstream of the desiccant rotor in the dehumidification passage; and an adsorptive cooler comprising an adsorber including a first sub-adsorber and a second sub-adsorber configured to adsorb a refrigerant at an adsorption temperature and desorb the refrigerant at a regeneration temperature, a condenser configured to condense the refrigerant, and an evaporator configured to evaporate the refrigerant, wherein the adsorber is connected to each of the external heat source and the regeneration preheater, and the regeneration preheater is heated by adsorption heat generated in the adsorber.