On Shenguang-III prototype facility, eight $ 3\omega $ (351.0 nm) laser beams are used to produce laser-scale high-temperature plasmas as well as to excite strong stimulated Brillouin scattering (SBS). An additional $ 4\omega $ (263.3 nm) laser beam, together with a large-aperture Thomson scattering diagnostic system, is applied to obtain the super-thermal collective Thomson scattering (STS) spectra of the ion acoustic waves driven by the SBS process of a $ 3\omega $ laser beam. By comparing and analyzing the STS spectra and the backward SBS spectra, the temporal and spatial evolution of SBS is revealed.