In order to realize highly accurate and stable clock signal extraction using Fiber Optical Parametric Oscillators (FOPOs), the idler-power-based automatic feedback control experiment is implemented for the first time. The automatic feedback control unit consists of idler acquisition module, signal processing module for automatic control, and delay line drive module. By means of the automatically feedback-controlled FOPO, a high-quality optical clock signal can be extracted from the 12.5 Gb/s Return-to-Zero (RZ) data sequence and the RMS phase jitter is 0.92 ps, much better than the results obtained in the previous manual feedback control system.