Abstract: In order to reduce the negative impact of loading dust on the occupational health of workers and external environmental pollution in low-concave open-pit mines, Fluent numerical simulation method is used to study the transportation law and mass concentration distribution characteristics of loading dust in the face of low-concave open-pit mines under the conditions of different mining depth conditions based on the theory of gas-solid two-phase flow. The results show that the mining depth has a significant influence on the loading dust diffusion mode and the loading dust mass concentration at the height of the breathing zone. When the mining depth H=0 m, the square column disturbance occurs due to the blocking effect of the ore car, and the loading dust particles escape from the cars and spread linearly along the X-axis, and the diffusion distance increases with the prolongation of diffusion time. When the mining depth H>0 m, the wind flow in the quarry at the step occurred flow separation, forming a large wind flow vortex with the same height as the mining depth. The loading dust particles escaped from the cars and diffuse around with the large structure vortex. With the increase of mining depth, the diffusion distance of loading dust particles along the X-axis gradually decreases, and the diffusion distance along the Z-axis increases, and the influence range of loading dust mass concentration exceeding the standard at the height of breathing zone downwind of the ore car decreases, and the mass concentration of the loading dust at the height of the breathing zone gradually decreases with the increase of the diffusion time and decreases to the occupational exposure limit of 8 mg/m³ or less at t=100 s. This paper provides decision-making reference for reasonably determining the pollution impact range of loading dust and formulating effective loading dust control measures.