The utility model discloses a check valve for acquiring gas. The check valve at least comprises an upper connector, an upper jacket, a center backflow connector, a lower jacket and a lower connector which are connected in sequence in a thread manner. The check valve is characterized in that a check valve component is fixed on the center backflow connector by a locking screw cap; and the center backflow connector is provided with a grit channel and a backflow hole which are intersected mutually but are not communicated mutually. The check valve can be assembled with a releasing packer so as to form a bridge plug capable of acquiring gas, replaces a bridge plug capable of dredging to be used for the partial pressure and partial evaluation and commingling construction of a low-pressure gas well, realizes the purpose of acquiring gas in a combined layer with no drilling and no dredging of the bridge plug, simplifies the technique process, improves the working efficiency, reduces the damage on an the air layer due to kill operation, opens the pressure needed by the channel, and can be adjusted according to the requirements.