In this paper, a new control method for a interleaved voltage-doubler boost converter is proposed to extend the operating range of duty ratio. Firstly, the analysis of the current-sharing mechanism is presented. Then, the averaging method is adopted to construct an average-behavior circuit model. After that, the modulation signal for current-sharing is particularly designed by amp-second balance. Besides, the average state-space equation of the voltage-doubler can be obtained. The open-loop transfer function can be derived from the small-signal analysis, and the proportional-integral (PI-type) controller parameters can be selected by Bode plots. All the algorithms are implemented in a Field Programmable Gate Array (FPGA) chip. The simulation and experimental results validate the inductor current-sharing capability of the proposed method.