outflow channel 6 pressurization stops after a required amount of the contained product is taken out the contained product stops flowing out the valve core 8 of the control valve 5 moves towards the pressure transfer channel 4 under the action of the spring 122 at the outflow channel 6 and the opening 19 and the outflow 6 are disconnected the opening 20 and the pipeline 14 are also disconnected the airbag 7 is released the airbag 7 attempts to recover to decompress the pressure transfer channel 4 that is to produce a negative pressure so that the valve core 8 of the control valve 5 moves upwards towards the pressure transfer channel 4 the opening 20 communicates with the pipeline 14 through the interface 16 and under the negative pressure the contained product 2 enters the pressure transfer channel 4 along the internal channel 13 of the control valve 5 after the airbag 7 recovers the pressure transfer channel 4 is filled with the contained product entering to make the negative pressure disappear the spring 121 at the pressure transfer channel 4 pushes the valve core 8 of the control valve 5 to move downwards towards the outflow channel 6 and the opening 20 and the pipeline 14 are disconnected the opening 19 and the outflow channel 6 are also disconnected the check valve 3 under the external atmosphere makes the external gas in the container body enter into the container until internal and external pressures of the container body 1 are equal because of the existence of the check valve 3 only a limited amount of outside gas can contact the contained product in the container body 1 which may reduce pollution or oxidization of the contained product as shown in fig6.