Abstract: An integrated system of positive pressure ventilation is often confined to the insufficient cooling for the multi-span greenhouses, due to the limited area of wet pads. In this study, a spray-based system of positive-pressure ventilation was developed to replace the wet pads with high-pressure fogging for evaporative cooling. The heat and mass exchange were enhanced for better cooling performance within limited space. The air conditioning unit and air ducts were combined to draw in ambient air. Then high-pressure fogging was used to cool the delivering air into the greenhouse via underground ducts. The humid and cool air was introduced near the ground using terminal air outlets. While the hot indoor air was discharged via the roof vents. The ventilation system was also tested in a multi-span greenhouse located in Wuzhong, Ningxia, China. A traditional cooling system of wet pad-based positive pressure ventilation was taken as the control. Results showed that: 1) The system with a shading screen maintained the average air temperature below 31.6 ℃ in the experimental area during summer daytime (8:00-18:00), there were 3.5 ℃ and 1.5 ℃ lower than the outdoors and the control area, respectively. The average relative humidity of 68% was 40% higher than that outdoors in the experimental area. Without shading, the vapor pressure deficits (VPD) in the experimental area ranged from 0.42 to 1.07 kPa, and 0.40 to 1.60 kPa lower than the control area. Nevertheless, the airflow velocity at the terminal outlets was uniform in the east-west direction (standard deviation: ±0.7-1.0 m/s) under the positive pressure ventilation. The airflow velocity difference between the north and south ends ranged from 4.1 to 6.0 m/s, with an average temperature difference of 0.5 ℃. Furthermore, the temperature increased vertically, whereas, the humidity decreased with the height; The maximum temperature and humidity differences were 3.7 ℃ and 13.7%, respectively, in the 1-5 m range from the ground. In the tomato canopy height range (1-3 m), the average temperature was 2.8 ℃ lower than that at the top of the greenhouse. As such, the cooling system of positive pressure ventilation effectively and accurately controlled the temperature and humidity. The ventilation system of spray-based positive pressure shared better cooling than the control. 2) The joint cooling was also recommended to combine with the high-pressure misting inside the greenhouse in the high-temperature period (11:00-15:00). The daily average indoor air temperature was 2.7-6.8 ℃ lower than the outdoor temperature. The cooling performance also increased by 0.7-4.2 ℃ in the combined system, compared with the positive pressure ventilation only. There was a more uniform spatial distribution of temperature and humidity in the vertical direction, with the standard deviations decreased by 0.2 ℃ and 1.7%, respectively. In a one-day test (July 16, 2023), the combined cooling of the two systems resulted in the minimum daytime temperature of 27.4 ℃, with a temperature difference of 8 ℃ from the outdoors. 3) The processed air was reduced by 10.5 ℃ with a 54% humidity increase, compared with the inlet. A cooling efficiency of 98% was achieved with the 3 percentage points higher than the control system. The power and water consumption of the system were 5.4-14.6 W/m² (greenhouse area) and 0.046-0.076 g/(m²·s), respectively, which was positively correlated with the outdoor VPD (P < 0.01, r² = 0.59). This finding can provide a cooling system for year-round, efficient, and high-quality cultivation under multi-span greenhouses in summer.