A cooling assistance device and a fan, in the technical field of cooling apparatuses, include: a first main body, a second main body, and a gas source driving member. A first delivery channel is provided inside the first main body, and one side of the first main body is provided with a first delivery opening in communication with the first delivery channel. A second delivery channel is provided inside the second main body, and one side of the second main body is provided with a second delivery opening in communication with the second delivery channel. The gas source driving member is configured to increase a flow rate of gas inside the first delivery channel. The first delivery channel is configured to deliver airflow to the first delivery opening. When the airflow flows out from the first delivery opening, a negative pressure region is formed at the second delivery opening.