Using high dynamic range X-ray framing camera, the radiation driven ablative Rayleigh-Taylor instability facing backlight radiography on SHENGUANH (SG) II device is studied. In the SG II that has eight beams with the 2 ns laser pulse and the ninth beam for Mo backlight, two-dimensional space-time ablation RT growth process for the cycle 20 m and the initial perturbation 1 m are observed clearly, and the non-linear growth process is also observed by the doping Br ratio of 1.1% in samples. The result lays a good foundation for quantitative characterization and numerical simulation of RT instability in inertial confinement fusion (ICF) experiments.