A single-tube blowing suction device, including a body, an airflow generation apparatus, a collection apparatus, and a blowing-suction tube. The airflow generation apparatus has an air inlet portion and an air outlet portion and is rotatably mounted on the body. The airflow generation apparatus rotates relative to the body to enable the single-tube blowing suction device to switch between a suction mode and a blowing mode. In the suction mode, the air inlet portion is in fluid communication with a first end of the blowing-suction tube, and the air outlet portion is in fluid communication with a connection port of the collection apparatus. In the blowing mode, the air outlet portion is in fluid communication with the first end of the blowing-suction tube. In the single-tube blowing suction device of the present invention, one tube is used for both blowing and suction.