The present disclosure provides a cooling system, including an air-cooling device and a water-cooling device. The air-cooling device includes a first fan, an evaporator, a first condenser, and a second fan. The first fan is arranged in a first cooling room and configured to blow a hot air inside a rack into a first cooling room. The evaporator is arranged in the first cooling room. The first condenser is arranged in a second cooling room. The second fan is arranged in the second cooling room and configured to blow an outside air into the second cooling room. The water-cooling device includes a radiator. The radiator is arranged in the second cooling room and configured to receive a hot liquid from an electronic device in the rack through a third pipeline and transmit a cold liquid to the electronic device through a fourth pipeline.