Taking the commercial salt as a model sample of granular matters with complex size and component distribution, we study the stability of laser-induced breakdown spectroscopy (LIBS) from microelements in complex granular matters. We measure the intensities of emission spectral lines, relative standard deviation and signal to noise ratio from four typical microelements (Ca with mass fraction of 800×10-6, Sr with mass fraction of 35.1×10-6, Mg with mass fraction of 6.4×10-6, and Fe with mass fraction of 1.7×10-6) in the salt sample in the band from 250 nn to 465 nm to determine the most optimal experimental conditions for synchronously detecting the four microelements. Based on these optimal conditions, we quantitatively obtained that the LIBS stability of the four microelements is above 10%, 14%, 13% and 28%, respectively. This indicates that LIBS technology has the ability to detect microelement with mass fraction of 10-6 in salt, providing experimental references for the detection of microelements in complex granular matters using LIBS in on-line industrial processes.