Gas leakage prevention device

The utility model discloses a gas leakage prevention device, and relates to the technical field related to mining. The device comprises a gas transfer tank, a bottom clamping shell, a fixing shell and a flexible connecting cylinder, the flexible connecting cylinder is fixed to the center of the top of the gas transfer tank, the top of the gas transfer tank is symmetrically and fixedly communicated with gas pipes, the bottom clamping shell is arranged below the gas transfer tank, and a flexible limiting ring is fixed to the bottom of the bottom clamping shell; a fixed shell is fixed to the top in the gas transfer tank, and a gas probe is fixed to the top in the fixed shell. Through the arrangement of the gas transfer tank, the bottom clamping shell, the fixing shell and the flexible connecting cylinder, the problems that an existing gas leakage prevention device cannot conveniently determine whether a rock stratum corresponding to gas is drilled or not and cannot reduce gas leakage into air before extraction e