A heat-dissipating device comprises a heat-dissipating member, at least one heat-dissipating fan, and a rotation control unit. The heat-dissipating member has an airflow chamber inside and includes a plurality of air-guiding holes in communication with the airflow chamber. Each of the at least one heat-dissipating fan has two air-guiding portions, wherein one of the air-guiding portions is aligned with one of the air-guiding holes of the heat-dissipating member. The rotation control unit communicates with and controls the at least one heat-dissipating fan. Accordingly, the heat-dissipating device with a dust auto-removing function can provide a balanced heat-dissipating effect.