Using 1.053 μm, 28 ns Nd:YLF laser as pump source, adopting 3:1 inverse expander, stimulated Brillouin scattering (SBS) in CS2 liquid media under non-focusing pump is investigated experimentally. The rules of SBS energy reflectivity and pulse width versus pump energy are acquired, and compared with the results of focusing pump. The experimental results indicate that, SBS can be generated under non-focusing pump as also, but the threshold energy increases largely, and energy reflectivity is lower than that of focusing pump, just 17% for 155 mJ input energy. The instability of SBS energy is 10%. The rules of SBS pulse width versus pump energy are almost consistent with that under focusing pump. The pulse width of SBS is broadened with the increase of pump energy, and has a minimum ～16 ns around threshold energy.