The invention discloses a weighted baffle of an exhaust valve. The weighted baffle structurally comprises an air pressure monitor, a circular fixed top plate, an exhaust net cover, an exhaust device,a fixing seat and a fixing hole. According to the exhaust device, air in a pipeline can be automatically guided into a gas collecting hood through a baffle weighted movable mechanism; along with large-quantity accumulation of the air, a floating ball triggering mechanism drives a motor to work, and the motor drives the exhaust mechanism to work, and the air accumulated in the pipeline can be largely eliminated through the exhaust mechanism; and once negative pressure is generated in the pipeline, the outside air can be quickly sucked in, pipeline damage caused by the negative pressure is prevented, and the working efficiency of the pipeline is improved.