Abstract: Hybrid cooling systems of thermal power generation have the advantages of large wet-cooling capacity and air-cooled water saving. It can also adjust different cooling methods according to the load conditions of the unit and the environmental meteorological conditions of the power plant, so that the unit has better flexibility and environment adaptability. In order to master the hybrid cooling performance of thermal power generation, a combined cycle cooling system test bench was established in parallel and series operation modes of dry and wet-cooling sections. The experimental research on the heat load distribution of the dry-cooling section and the wet-cooling section in hybrid cooling system under different operation conditions was carried out. Changes law of water consumption and cooling capacity under different operation modes was determined. Univariate analysis method was used to study the influence of environmental temperature, environmental humidity and other factors on the performance of hybrid cooling systems. The results show that after the ambient humidity increases, the different operating modes of the system are affected by the decrease of the circulating water evaporation rate, and the heat dissipation and water consumption are reduced. What is more, quantitative results are obtained with the increase of ambient temperature and the decrease of the heat transfer temperature difference, revealing the changes law of water consumption with the proportion of heat load distribution in dry and wet-cooling sections. The research results provide an experimental basis for optimizing the operation mode and heat load distribution ratio of hybrid cooling system under different meteorological conditions.