To address the problem that indirect evaporative cooling technology is limited in high humidity areas, this paper establishes an evaporative cooling system with dehumidification system, which uses the waste heat of data center and solar energy as the regenerative heat source of dehumidification bed, and introduces the selection method of the main equipment of this system; the performance of data center using this system in Guangzhou is analyzed and compared with the conventional mechanical refrigeration system. The results show that the PUE of the conventional mechanical cooling system is 1.4, and the PUE of the combined heat source system is 1.21, which is better than that of the conventional mechanical cooling system; the power consumption and carbon emission of the combined heat source system are much lower than that of the conventional cooling system, which shows a superior energy saving level.