Industrial bulk material transfer and handling processes often result in large dust emissions and seriously threaten workers' health. Both dust dispersion and ventilation for dust removal are related to the entrained air flow field under the particle flow fall process. The PIV test system is used to test the entrained air flow field during the particle flow free and adheres wall fall process. The particle flow free fall process: The entrained air velocity show a Gaussian distribution at the different height sections. The particle diffuses mainly along the width-side (d), and the diffusion phenomenon is not obvious in the length-side(l) direction. The particle flow adheres wall fall process: When s/d <= 5, the existence of the vertical wall has a significant effect on the entrained air flow field, and the entrained air can better adhere to the vertical wall. When s/d>5, the existence of the vertical wall has a little effect on the entrained air flow field, and the entrained air is basically separated from the vertical wall. This study provides a theoretical basis for the ventilation design of industrial particulate transport systems (C) 2020 Elsevier B.V. All rights reserved.