The navel orange is analysed quantitatively for cadmium by laser-induced breakdown spectroscopy. The laser-induced breakdown spectroscopy is used to obtain the characteristic spectrum of Cd in sample. The concentration of sample is detected as a reference concentration by atomic absorption spectrophotometer. The partial least squares method is applied to the data of 39 samples which are preprocessed by combining the five smoothing formula and centerization method to establish quantitative analysis of cadmium model. Other 13 samples are used to be compared with the results from the quantitative analysis model. In this model, the correlation coefficient of fitting curve is 0.9806 and the relative error of 12 samples is 10.94 percent. The research results show that laser-induced breakdown spectroscopy can nondestructively and accurately detect heavy metals in agricultural products without preparing any sample and provides a technology for the safety of agricultural products.