Based on the issues of the gas easy gather in the upper corner and transfinite in the return corner on working surface,this paper uses the method of Fluent numerical simulation to build the math pattern of the gas migration in mechanized coal face,introduces local-ventilator "blows away" the upper corner gas and fully-mechanized caving roadway by gas tail regulate with gas migration in gob.The results show that the upper corner gas disturbance effect is the best when the local-ventilator wind speed is 20 m/s,and it also determines that the face wind amount being 1 900 m3/min and caving roadway step away from the upper corner being 50 m is the best effect on gas prevention.The numerical research results can provide some theoretical reference for the gas controlling in the upper corner.