Abstract: Taking the middle section 4 470 m of Jiama copper mine as the research object, aiming at the safety problem caused by the diffusion of blasting smoke in high altitude metal mine, the numerical simulation of the diffusion law of blasting smoke in high altitude metal mine is carried out by using Fluent software.Based on the simulation results, the influence of air volume on CO transport is studied from two aspects of air volume of 1.56 m³/s and 2.03 m³/s respectively.Based on the premise of air volume Q=2.03 m³/s, the effects of different air duct diameters and the distance between the air duct mouth and the palm face on CO transport are analyzed.The risk evolution of blasting smoke in the diffusion area after blasting is analyzed, and the CO migration rule during ventilation is studied from the distribution area of CO in the roadway.The results show that when the air volume is 2.03 m³/s, the diameter of the air duct is 0.5 m, and the ventilation time is 1 580 s, the CO concentration value in the roadway has met the safety standard for underground operation.The distance from the air duct mouth to the face of the tunnel has a negative correlation with the elimination speed of CO in the roadway.At the same time, it should be combined with other influencing factors to optimize the underground ventilation effect.Based on the above rules, the smoke diffusion area is divided into four areas:safe area, sub-safe area, moderate danger area and danger area, and the relationship between ventilation time and air volume is obtained.