Lead-based reactor is rated as the first fourth-generation reactor expected to achieve commercial application by Generation IV International Forum (GIF). The coolant of lead-based fast reactor can corrode metals. The existence of impurities in coolant will affect the safe operation of the lead-based reactor. Under this background, the application of impurity measurement in lead-bismuth alloy with laser-induced breakdown spectroscopy (LIBS) technique was studied. The effects of laser focusing position, laser energy and delay time on Ni elements spectral signal were studied. The optimal experimental parameters for measuring impurities in lead-bismuth alloy with LIBS device were obtained. At the same time, quantitative analysis of Ni element in lead-bismuth alloy was performed by employing LIBS technique in the present paper. The coefficients of determination gained by internal standard method is 0.967. The detection limit of mass content is 0.0287%. The results show that it is feasible to use the laser-induced breakdown spectroscopy technique to measure impurities in lead-bismuth alloy. LIBS technique has high application research value in the field of advanced nuclear energy.