The invention discloses a method for detecting the content of copper in rice based on laser-induced-breakdown spectroscopy. The method comprises the steps that 1, a series of solutions with the gradient of different copper element concentrations are prepared, the copper element content is adopted as the gradient, and rice samples soaked inside the solution are ground, screened and tableted as detection samples; 2, laser-induced-breakdown spectroscopy data X of the detection samples is obtained; 3, a flame-atomic absorption spectrometry is selected for measuring the real content of the copper element in each concentration sample, and the real content is recorded as Y; 4, according to the corresponding relation between wavelength and the elements, the wavelength, where the wave crest is located, corresponding to all copper elements is found from original LIBS spectroscopic data, and the wavelength is recorded as X1; 5, after abnormal points are removed from data in the X1, and data X2 is obtained; 6, by means of linear fitting, the X2 is adopted as input, Y is adopted as output, and a linear regression model is built; 7, quantitative analysis is performed on the copper content in a certain number of samples by means of the linear regression model, and the model accuracy is verified.