An active heat-dissipating type of power supply apparatus includes a casing, a first airflow channel, a second airflow channel, plural electronic components, an airflow driving device and a power input device. The casing includes at least one first airflow opening. The first airflow opening is communicated with the second airflow channel. The electronic components are disposed in the first airflow channel. The airflow driving device includes an airflow gate. The power input device is disposed on the first side of the casing and in the second airflow channel. A cooling air is pumped by the airflow driving device to be introduced into the second airflow channel through one of the first airflow opening and the airflow gate, so that the heat generated from the power input device is exhausted through the other one of the first airflow opening and the airflow gate.