Universal serial bus charging device

A charging device includes a charger (1) provided with a first transmission line (11) and a second transmission line (12) respectively on two ends thereof. Two respective first ends of the first and second transmission lines (11, 12) are connected with a circuit in the charger (1). The second end of the first transmission line (11) has a USB connector (2) so as to be connected with the USB interfaces of electronic products (6). The second end of the second transmission line (12) has a connector (3) which is connectable to a Lithium battery (5). The charger (1) charges the Lithium batteries (5) via the USB interfaces of the electronic products (6).