The invention relates to an optical frequency comb device based on an all polarization-maintaining fiber and a mode locking and frequency locking method. The generation of mode locking pulses is realized by nonlinear polarization rotation of the pulses in a spiral fiber. The repetition rate of the device is locked through a mechanical method or an optical method. Through an all polarization-maintaining fiber amplifier, a polarization-maintaining nonlinear fiber and a PPLN crystal, carrier phase zero frequency signals of the pulses are acquired; the carrier phase zero frequency signals are processed by a circuit and are then fed back to a power control device in the device or fed back to an intracavity loss control device, and locking of the carrier phase zero frequency signals is realized.Based on the all polarization-maintaining fiber, a mode-locked laser is built, the pulses generate nonlinear polarization rotation in the spiral fiber, and walk-off effects of the pulses are solved through special arrangement of multiple sections of spiral fibers. The made all polarization-maintaining fiber optical frequency comb device has the characteristics of extremely high stability and insensitivity to temperature fluctuation and mechanical vibration.