Novel centralized gas extraction box

The utility model discloses a novel centralized gas extraction box which comprises a box body; a supporting leg is arranged at the bottom of the box body; a water-drainage and air inlet pipe is arranged on one side of the top of the box body; a group of gas extraction air inlet pipes are arranged at the front part of the box body; a branch pipe connector is arranged at the middle position of the top of the box body; a water baffle plate is arranged above the gas extraction air inlet pipes in the box body; and a water-drainage pipe is arranged at the bottom of the box body. Connection with a branch pipe is more convenient and faster; the position of the water-drainage pipe on the side surface of the box body is replaced by a position under the box body, so the water drainage is more thorough; a water level meter is added for clearly observing a water level in the box body and providing a reliable basis for water drainage; a sewage drainage hole is formed so that plugging of the box body is easier to treat; the