The invention discloses a compact and stable high-peak-power optical fiber output laser. The laser comprises a resonant cavity, pumping sources, a half-wave plate, a polarization beam splitter, a photoelectric detector, a coupling lens, an optical fiber and a collimating lens group, wherein the resonant cavity comprises a Porro prism, a passive Q-modulation crystal, a laser crystal and an output mirror; in the compact and stable high-peak-power optical fiber output laser, the Porro prism, the passive Q-modulation crystal, the laser crystal, the output mirror, the half-wave plate, the polarization beam splitter and the photoelectric detector are arranged in sequence in a light path direction of laser; the pumping sources are uniformly arranged in the center of the laser crystal by using stack arrays; the polarization beam splitter splits the laser into a branch light path perpendicular to the light path; the laser on the branch light path enters the optical fiber through the coupling lens; and the collimating lens group is arranged at the end of the branch light path. According to the compact and stable high-peak-power optical fiber output laser, the stability of a system is ensured, the risk of optical fiber damage is lowered, and the peak power of the optical fiber output laser is indirectly increased.