A current sharing apparatus and a method thereof are provided. The current sharing apparatus comprises an input terminal, an output terminal, a current-sharing control terminal, a pass transistor, a constant voltage generating unit, a feedback control circuit and a current-sharing control unit. The current-sharing control terminal provides a current-sharing control interface. The pass transistor receives an input voltage and provides an output voltage and an output current. The feedback control circuit senses the output current to provide a current-sense signal and regulates a control signal of the pass transistor for controlling an output of the current-sharing apparatus. Moreover, the current-sharing control unit electrically coupled to the current-sharing control terminal and the feedback control circuit generates a bus signal in response to the current-sense signal and a reference voltage and generates a reference signal in response to the reference voltage, the bus signal and the current-sense signal.