Abstract: At present, it is difficult to adjust the air flow at the outlet of the wind pipe dynamically by the total ventilation control method commonly used in the excavating face, resulting in insufficient air volume or unreasonable air flow distribution, and causing safety hazards such as gas and dust accumulation. Taking S1200-Ⅲexcavating face of Ningtiaota Mine as an example, by analyzing the problems of the original wind field and the requirements of wind flow control, the air flow control device is designed, which installed a mechanical structure driven by a pneumatic cylinder or a pneumatic motor. The device is able to realize the dynamic adjustment of outlet deflection angle, caliber size and front-back displacement. This paper introduces the design scheme of mechanical system, pneumatic actuation system and control system of the device. ANSYS Workbench software is used to conduct finite element analysis on the safety of the mechanical system. The results show that the maximum stress is 87.2 MPa, the safety factor is 2.69, the maximum deformation is 0.84 mm, and the average deformation is 0.42 mm. FluidSIM software is applied to simulate and analyze the pneumatic actuation system. The results show that the device can complete the predetermined action and run smoothly and reliably. Underground test results show that after adopting this device, the air flow distribution at the driver and pedestrian breathing zone height is more reasonable. When the air duct outlet is 5 m away from the working surface, the dust concentration at the driver and pedestrian breathing zone is reduced by 45.3% and 33.4% respectively compared with situation before the control. When the air outlet is 10 m away from the working face, the concentration is reduced by 40.4% and 34.3% respectively.