The invention discloses a gas monitor capable of automatic exhausting. The gas monitor comprises an exhausting fan, a carbon monoxide sensor, a relay, an intelligent switch, a power supply and an alarm, wherein the exhausting fan is connected with the alarm, the alarm, the power supply and the relay are connected with the intelligent switch, and the carbon monoxide sensor is connected with the relay. The gas monitor capable of automatic exhausting can detect the content of carbon monoxide automatically, automatically power on the exhausting fan when the content of carbon monoxide exceeds a set value, exhaust carbon monoxide indoor rapidly, and raises the buzzing type alarm; and the gas monitor is simple and reasonable in structure and low in manufacture cost.