Laser-induced breakdown spectroscopy (LIBS) was applied to directly detect the coal particle flow. An investigation of the impact of different spectrometer detector angles measured from the laser incident axis on the plasma properties was conducted on the self-built two-phase particle flow experiment bench. Coal particle flow was used as the experimental sample. An analysis of the variation in the emission intensity and relative standard deviation (RSD) was carried out. The atomic spectral lines of C, Si and Al which are representative elements in coal were chosen as the analytical lines. Then the influence of the spectra acquired with different collection angles was discussed. The results demonstrated that the strong and stable intensity signal can be acquired in the collection angle range from 30° to 45°.