Abstract: Solar energy is widely used under the carbon neutrality target of carbon peak. The increase of the temperature of the photovoltaic panel will significantly reduce the photoelectric conversion efficiency, so the effective cooling of the photovoltaic panel is the key to improve the efficiency of solar power generation. Aiming at the problem of high temperature and low efficiency of photovoltaic panels on sloping roofs in rural areas, this paper proposes a method to optimize heat transfer in photovoltaic systems on sloping roofs by adding partitions to the air flow channel between photovoltaic panels and roofs to take advantage of the “chimney effect”. Based on this method, a slope roof photovoltaic experimental platform was built, and the verified CFD model was used for numerical simulation. By comparing the width-to-height ratio of the flow channel between five different baffles, the optimal width-to-height ratio is determined to be 1∶1. Based on this model, the effects of ambient wind speed, roof inclination and photovoltaic array length on the “chimney effect” are studied. The results show that the average temperature of photovoltaic panels decreases with the increase of the ambient wind speed, roof inclination angle and photovoltaic array length. When the ambient wind speed increases from 0.2 m/s to 5.0 m/s, the average temperature of the photovoltaic panel decreases from 64.31 ℃ to 49.06 ℃. When the roof inclination angle increases from 20° to 35°, the temperature of each part of the photovoltaic panel decreases slowly. When the roof inclination angle increases from 35° to 50°, the temperature of each part of the photovoltaic panel decreases faster. The average temperature on the photovoltaic panel decreased from 61.62 °C to 55.66 °C. When the length of the photovoltaic array increases from 1 to 5, the average temperature of the photovoltaic panel decreases from 64.68 °C to 57.65 °C.