A handheld device with a fast-charging capability is adapted to be connected to a charger to obtain an electric power. The handheld device includes a battery, a charging circuit, a safety circuit, a control unit, and an input module. The charging circuit is electrically connected to the charger and transfers an electric power to the battery. The safety circuit is used for restricting an upper limit of the electric power transferred by the charging circuit. The input module is provided for a user to input an emergency charge command. Upon receiving the emergency charge command, the control unit instructs the safety circuit to lower the restriction on the charging circuit, so as to raise the upper limit of the electric power that can be obtained by the charging circuit, thereby accelerating the charging of the battery.