In order to adapt the requirement of experimental teaching in nuclear physics and nuclear analysis, laser-induced breakdown spectroscopy (LIBS) is introduced to the experiments of nuclear engineering as an innovative demonstration experiment. Experimental measurement of LIBS spectra is performed during the interaction between nano-second laser pulses with different targets. The electronic temperature and density of laser plasma are extracted combining with theoretical analysis. The plasma density obtained from the characteristic spectral line of solo element is assumed to the plasma density of the mixed target, and the unknown spectral broadening parameter of Fe(I) is calculated.