Abstract: Abstract: The introduction of baffles can effectively improve the efficiency of flat plate solar air collector. But at the same time, it is found that the flow separation on the back side of the baffle leads to the generation of local vortex, which causes the airflow to be heated in the corresponding position. The local temperature is higher and the heat loss is serious. This has become an important factor affecting the further improvement of the efficiency of solar air collector. Based on the aerodynamics of wind wall, the author is aim to open holes on the baffles without changing the whole structure of collector. Thus, we can use the hole jets to enhance the turbulence and mixing of the flow at the back side of the baffle, suppress the local vortex and reduce the heat loss; Also, the hole jets can enhance the convection heat transfer of air and heat absorber plate, which can make more heat into the air, and then achieve the purpose of improving the efficiency of solar air collector. The paper studies the impact of different parameters on solar air collector with holes on the internal baffles by using orthogonal numerical simulation test method. Considering the interaction between aperture factors, an L27(313) orthogonal experiment is designed with four factors and three values including hole size, location, quantity and mass flow rate. 27 solar air collector models with holes on the internal baffles are designed, and the three-dimensional numerical simulation of the designed condition is carried out. The efficiencies of the 27 designed collector models are obtained. The simulation results by variance analysis method are analyzed. The variance analysis is used to determine the significant level of the factors by F test. If the ratio of the F ratio and the critical value is greater than 1, it is considered that the factor has a significant effect on the collector efficiency. The results show that the interaction between the hole factors is not obvious. The effect of inlet mass flow rate and the hole size on collector efficiency is significant. The hole factors under different inlet mass flow rate effect on the collector efficiency in a different order. The optimal hole factors combinations under different inlet mass flow rate is different. When the inlet mass flow rate are0.0044, 0.0088 and 0.0132 kg/(s?m2), the optimal hole factors combinations with the highest efficiency are hole size of 1/6, location of 1/3, quantity of 3; hole size of 1/3, location of 1/3, quantity of 5; hole size of 1/3, location of 0, quantity of 5; the heat collection efficiency is 69.63%, 81.71% and 86.83% respectively. In this paper, the results could provide theoretical support for design and improvement of solar air collector with baffles.