Gas flow controller

The utility model discloses a gas flow controller which comprises a controller body, a gas conveying pipe penetrates through and is fixedly connected to the bottom of the left side of the controller body, a filter box penetrates through and is fixedly connected to the left side of the gas conveying pipe, and a sealing cover penetrates through and is slidably connected to the center of the top of the filter box. A filtering piece is fixedly connected to the center of the bottom of the sealing cover, and a sealing piece penetrates through and is fixedly connected to the middle of the periphery of the outer surface of the sealing cover; dust and water vapor in gas input from the outside can be filtered out through a filter plate in the filter box, the sealing performance of the filter box is further improved through mutual cooperation of a sealing cover and a sealing ring filled in a sealing groove, meanwhile, a compression spring presses a pressing plate downwards under the action of resilience force of the com