A heat dissipation device, a heat dissipating method, and a terminal are described. In an embodiment, the heat dissipation device, a heat dissipating method, and a terminal are configured to correspondingly form at least one ventilation wall that is configured to dissipate heat on different heat source positions of the terminal, and form a flow path of the heat dissipation airflow generated by the at least one ventilation wall, based on different heat source positions of the terminal in different applications. In an embodiment, the entire heat dissipation of the terminal can be achieved by the flexible and variable flow path to provide a good user experience.