For a better application of laser-induced breakdown spectroscopy (LIBS) to coal quality analysis, it is necessary to optimize the key parameters of the experimental LIBS-based device. The relationships between the key parameters and the signal-to-noise ratios (S/N) of the elemental emission lines in the plasma spectrum of the pulverized coal were studied, according to which the optimal parameters can be selected. Experimental results indicate that the optimal settings for our LIBS-based device are laser pulse energy=120 mJ·Pulse-1, delay time of spectrometer=200 ns, laser focal point be located 3～5 mm underneath the sample surface, rotation speed of sample cell=2.7 rev·min-1, a narrow-band filter with center frequency of 1 064 nm and a diaphragm with center hole diameter of 1.5 mm be placed in the path of the laser beam. Quantitative analysis results of pulverized coal show that, by using the optimal LIBS-based device, the standard deviation (SD) of C has been reduced from 6.7% to 1.6%, while the relative standard deviation (RSD) of other trace elements has been reduced from 28% to 10%. As a result, the accuracy has been improved greatly.