In order to realize the rapid quantitative detection of heavy metal cadmium (Cd) in table salt, 8 groups of salt samples were made by adding heavy metal element Cd and the self-made 193nm excimer laser was used as excitation source. By choosing Cd Ⅰ 228.8nm characteristic spectrum line as analysis line, laser induced breakdown spectroscopy (LIBS) technology was used in theoretical analysis and experimental verification. The experiment results show that, when the delay time is 1.5μs, the better spectral intensity and signal-to-background ratio can be obtained. The spectral line strength has a good linear relationship with mass fraction of Cd . The fitting degree is 0.984, the predicted relative error is less than 7%, and the detection limit is 0.65mg/kg. LIBS detection technology not only has the fast and convenient advantages without the need of tedious sample preparation, but also has high detection precision. It is a very novel and potential detection technology in the field of rapid detection of food safety.