High-quality shock waves were produced using the ninth laser beam (converted to 2ω) of Shenguang-II laser facility and the beam smoothing technology of a lens array. The spatial uniformity of the shock wave was estimated by measurements of the self-emission from the target rear surface. An Al–Au four-step target with 30 μm Al base and four Au steps was fabricated and used to investigate the temporal steadiness of the shock wave in the Al–Au two-layer target. The Al–Au four-step target experiment indicated that the shock wave steadily propagated in the Au material with thickness range ≪11 μm. A modified Al–Au impedance-match target was designed, which could simultaneously measure shock-wave stability and Au Hugoniot data in one shot. The experiment results indicated that the shock wave steadily propagated in the Al target with thickness of about 30–47 μm under a power density of ∼1.0×1014 W/cm2.