Sunscreen is a common semi-fluid substance, and it is difficult to obtain better results by direct ablation and detection by laser-induced breakdown spectroscopy (LIBS). The effects of film thickness and substrate material types on spectral signals were discussed, and the optimal experimental conditions for LIBS detection were determined. Under optimal conditions, the detection limit of Cd element was calculated by linear fitting to be 2.17 μg·g^-1, which has reached the national standard. The results prove that LIBS technology can be used for the quantitative analysis of heavy metal elements in sunscreen, which provides a basis for the detection of heavy metal elements in cosmetics.