Abstract: The 21606 working face of Qinglong Coal Mine adopts the entry retaining by roof cutting technology, and the ventilation mode is the "Y" ventilation mode of "one inlet and two return". Facing the problems of wide air leakage range and large air leakage in the goaf, it is very easy to cause the residual coal in this face and adjacent goaf to ignite naturally.In this regard, taking 21606 working face as the research object, firstly, the distribution of air leakage field in goaf with entry retaining by roof cutting is studied through COMSOL numerical simulation. The numerical simulation results show that:Under the "Y" ventilation mode of entry retaining by roof cutting, the air leakage wind speed in the goaf decreases significantly along the direction away from the fully mechanized mining face. The air leakage path in the goaf mainly enters from the lower corner and flows through the goaf to the upper corner and the ventilation eye.The air leakage prevention measures taken for different areas mainly include: building walls and shotcreting at the cut-off roadway and ventilation vertical hole; The roof cutting blasting is carried out in the working face to accelerate the roof collapse; Sand bag wall shall be built at the upper corner of the make-up track and the track, and Schmidt air leakage proof material shall be sprayed; Shotcreting shall be carried out at the cut hole and make-up cut hole, and the gas drainage hole of the cut hole shall be blocked in time; And spray inhibitor, pressure gel injection and other measures.Through the above comprehensive air leakage prevention measures, the safe mining of the working face is ensured.