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Spray concentration tower, as an important system component, plays an indispensable role in solar energy air evaporating separation saline wastewater treatment system. In order to explore the best heating forms in the concentration process, the heat and mass transfer performance of the counter-flow spray concentration tower is investigated through CFD simulation and experiment. The results reveal that increasing the temperature of inlet wastewater is beneficial to accelerating the evaporation rate and evaporation efficiency. However, increasing the air inlet temperature increases the evaporation rate but decreases the evaporation efficiency. Meanwhile, when the heat carrier is wastewater, the heat and mass transfer performance of the tower is much better than that of heating supplied air, especially in dealing with the high concentration wastewater. According to the simulation, when the simultaneous heating type is utilized, there will be a phenomenon that the heat transfer direction will change, which leads to the situation that the air temperature decreases first and then increases through the direction of the tower height. It is found that this phenomenon is conducive to mass transfer. This is because heating wastewater solution not only increases the temperature difference but also increases the surface steam pressure. The performance of the experiment system in different heating modes is also compared. The simultaneous heating type spray concentration tower system has the highest GOR (up to 0.7162). Compared with the air heating type system, the GOR is increased by 22.5–27.2%, while the GOR is increased by 1.35–2.65% compared with the wastewater heating type system.