Abstract: The metal mine has high concentration of deep dust， long duration， wide pollution range， and serious damage to the workers. In order to solve the problem of dust return pollution at the unloading port of high-deep straight shaft， aiming at the characteristics and production status of the unloading operation of shaft，the characteristics of the dust returning from the unloading of shaft were analyzed， and the induced air volume generated by the dust return after the unloading of shaft was studied. Based on the study on the characteristics of the returning dust and the induced air volume， control measures for the closed dust extraction and purification were proposed. Combined with numerical simulation of Fluent software，the key technology of closed dust control and dust extraction air volume were studied in depth， the closed dust control method of well pass was improved，and the dust volume was determined.Aming at the continuous operation characteristics of unloading operation surface，a new dust control technology of air curtain on unloading working surface with large cross section and open space was put forward，combined with rigid closed system， the complete airtight dust control of the well pass was realized.According to the current production status of high-deep straight-through shaft in Xiadian Gold Mine，the application on the dust-removing and dust-cleaning technology of shaft was done.The results indicated that after the treatment ，the total dust concentration in the shaft was reduced from 378.3 mg/m3 to 5 mg/m3， and the dust reduction efficiency is 98.7%. The respiratory dust concentration was decreased from 133.3 mg/m3 to 3 mg/m3， and the dust reduction efficiency reached 97.7%，the dust control effect was good. The surrounding environment of the wellhead before and after treatment was obvious.The study results show that the full airtight system combining air curtain dust control and rigid airtight could realize the transparent and airtight dust control on the unloading working surface of large cross section open space，and is equipped with the high-efficiency wet dust collector suitable for treating air volume，which is help for solving the problem of dust pollution in high-deep straight shafts.

Key words: high-deep straight shaft, back dust, discharge side, induced air volume, closed dust control, dust reduction efficiency