Microwave heating automatic exhaust bag

The utility model relates to the field of flexible packaging, in particular to a microwave heating automatic exhaust bag which comprises a bag body, a through hole is formed in the bag body, and an exhaust part is arranged at the through hole. The exhaust part comprises a hollow air cap with two open ends, the inner diameter of the air cap is gradually reduced in the axis direction, the end, with the smaller inner diameter, of the air cap is communicated with the containing space of the bag body through a through hole, a sealing piece is arranged at the other end of the air cap, an air plug slides in the air cap, a pressure spring is supported between the air plug and the sealing piece, and an exhaust hole is further formed in the air cap; a mounting ring piece is arranged at the position, opposite to the through hole, of the inner wall of the bag body, a clamping ring groove is further formed in the side, opposite to the air cap, of the mounting ring piece, and a plurality of flexible clamping hooks used for