Gas sampling bag valve with seal rings moving back and forth to control lateral gas nozzle

Disclosed is a gas sampling bag valve with seal rings moving back and forth to control a lateral gas nozzle. The gas sampling bag valve is easy to operate and not prone to leak gas. A valve body with the lateral gas nozzle, a rubber gasket, gas sampling bag film and a bottom disc of a fastening part are arranged in the connecting position of the valve and the gas sampling bag film sequentially from outside to inside, and the fastening part is rotated clockwise so as to fix the valve to a gas sampling bag. One seal ring, close to a rotary knob, of a top cover control switch can prevent gas leakage in gaps of the top cover control switch and a valve body screw thread, and when the top cover control switch rotates clockwise or anticlockwise, the other seal ring moves back and forth in a lateral hole of the valve body so as to open or close the valve. When the valve is closed, the seal ring, far from the rotary knob, of the top cover control switch is located on one side, far from the rotary knob, of a lateral gas nozzle hole of the valve body. When the valve is open, the two seal rings on the top cover control switch are located on one side, close to the rotary knob, of the center of the valve body lateral hole.