Abstract: According to aerdynamics,ignition process of the laser-supported-detonation (LSD)wave is analyzed and the expressions of the propagation speed, pressure and internal energy of laser-supported-detonation (LSD) wave are derived. The interaction of Nd:YAG laser beam and a pure Al targetplate is experimentally investigated with a Mach-Zehnder interferometer, and the series of interferograms of ignition and propagation process of LSD wave are abtained. The propagation speeds obtained from the theoretical calculation and experimental results are 2.54×104 m/s and 2.2×104m/s at the moment of 20ns time delay, respectively. The time variation curve of the propagation speed of LSD wave and the distribution of the electron desity in plasma are measured. These experimental results are use full to theresearch on the theoretical model of LSD wave.