Abstract: The Nd: YAG pulsed laser with 1064 nm wavelength was used as a light source to produce laser-induced plasma on the surface of the aluminum alloy, and the spectral signal was detected with three-grating spectrometer and width controlled ICCD. The intensity and the signal to background ratio of two characteristic lines of Al Ⅰ 394.40 nm and Al Ⅰ 396.15 nm were analyzed. It is shown that the delay of the ICCD detection, the width of the ICCD gate and the energy of laser pulse have great influences on the spectral signals and the signal to background ratio, and the variation of the width of the ICCD gate leads to the fluctuation of the signal to background ratio. By optimizing the parameters, the optimum conditions were determined, and high spectral intensity and signal to background ratio were obtained under low laser energy. The experimental results lay a foundation for the qualitative and quantitative detection of the components of the aluminum alloy.