Since most media of stimulated Brillouin scattering(SBS)are gases or liquids,the thermal collection or release within them will influence badly and destroy ulteriorly generation of SBS and its conjugation quality when the repetition rate was augmented or the duration of pumping pulse was prolonged adequately. It was experimentally investigated that effect of divergence of pumping beam on repetition operation characteristic of Brillouin cell in MOPA(Master-oscillator-power-amplifier)system with phase-conjugation mirror for improving the performance of SBS with high repetition frequency. The results show that repetition operation rate of Brillouin cell can be increased and the temporal and spatial characteristics of SBS can be improved,but the SBS threshold was increased and the pumped energy range of Brillouin cell was decreased with the divergence of pumping beam was decreased. Meanwhile,the fidelity decrease somewhat.