To compensate the drift of fiber loop length in fiber-optic parametric oscillator (FOPO), a novel feedback control scheme based on four-wave-mixing idler power is put forward. The feasibility of this scheme is confirmed by the clock extraction experiments for 10 Gbit/s optical return to zero (RZ) signal, and the normalized phase and amplitude jitter of less than 0.015 and 0.06 can be achieved under long-time stable operating condition. Thus, the scheme proposed in this paper is of practical applicability for the FOPO′s stability of oscillation.