A two-cell SBS phase-conjugating mirror pumped by pulsed Nd∶YAG laser was experimentally investigated. After returned to YAG amplifer and coupled out by a polariser, SBS output beam had the characteristics of duration tunability and good quality with near-diffraction-limited far-field divergence angle. The stability on SBS ouput energy and far-field divergence angle with the change of pump energy and separation between SBS generator and amplifier cells was also studied. By choosing pump energy, the fluctuation on SBS output energy and far-field divergence angle could be controlled within 5%.