A hub supplying power actively includes an active power supply device having a battery charger, a storage battery, a DC/DC converter, and a control circuit. The hub is connected to a USB of a computer to receive direct current (DC) of the USB. When power demand of the hub is lower than the DC power supply of the USB, the power is supplied by the USB and the storage battery is charged via the battery charger simultaneously. When power demand of the hub is higher than the DC power supply of the USB, the storage battery discharges electricity and supplies power after conversion by the DC/DC converter. When the hub is disconnected to the computer, a power adapter is connected externally to rectify mains electricity and to charge battery. The charged battery outputs the power to supply for the connected peripheral equipment after converting the electricity into direct current.