An electronic apparatus and a charging method thereof are provided. The electronic apparatus includes a transmission port, a battery module, an apparatus circuit, a power conversion circuit, a switching circuit, and a control circuit. The transmission port is coupled to an external power apparatus to receive an input power. The apparatus circuit and the battery module are connected to each other in parallel and are coupled to a power bus. Each of the power conversion circuit and the switching circuit is coupled between the transmission port and the power bus. When the external power apparatus is a programmable power supplier and a battery voltage is lower than a reference voltage, the control circuit disables the power conversion circuit, enables the switching circuit to transmit the input power to the power bus, and regulates a voltage value and a current value of the input power dynamically.