Abstract: A fan airflow-guiding device matches a cooling fan. One side of the cooling fan has an outlet. The fan airflow-guiding device includes a frame and a plurality of airflow-guiding boards. The frame is assembled on one side of the cooling fan. The airflow-guiding boards are disposed on an outlet of the cooling fan in a predetermined direction and in parallel. The airflow-guiding boards are pivoted in the frame, and its slanting angle is adjustable. Thereby, by adjusting the slanting angle of the airflow-guiding boards, the airflow exhausted from the cooling fan is guided to a predetermined location and the airflow direction of the cooling fan is adjusted.