An airflow detection device for detecting whether an air output path is obstructed can be mounted in the air output path and includes a carrying portion, a metallic sensing portion and a metallic air plate portion that are respectively positioned on the carrying portion and have different electrode polarities, so as to detect obstruction of the air output path. The airflow detection device can be applied to products located in remote areas, mountain areas, or other places where maintenance workers cannot inspect the products frequently for the state of their dust screens or ventilation holes, and can help warn of conditions such as ventilation hole obstruction to avoid product overheating due to dust or dirt accumulation on dust screens or ventilation hole obstruction, adverse impacts on product performance, service live or stability, or system crash.