Abstract:control,the axial velocity distribution law of the slot side gas-collecting hood under jet action was stud⁃ied. The influence of exhaust air volume on the dimensionless axial velocity without jet and the flowfield characteristics of the gas gathering system under the condition that the jet velocity was equal to thewind speed at the hood were analyzed by numerical simulation. Based on the results of the numericalsimulation,the variation laws of wind speed controlled by the jet angleAjand jet slot lengthLsvaryingin different ranges were compared. The results show that the exhaust air volume does not affect the vari⁃ation of axial velocity. The velocity attenuation becomes slow when the air supply ejects airflow in theopposite direction of theAj. WhenAjis -10°,the control wind speed reaches the maximum value,whichis 0.76 times of the wind speed at the hood. The optimum value ofLsis 0.4 times the width of the work⁃table,andVc= 0.57Veat this time. When the value ofLsexceeds the above value,the control windspeed will not increase. Close-