The fluorescence properties of imidacloprid was studied based on the basic theory that organic molecules can emit fluorescence as they are excited by rays. The fluorescence spectra were obtained under the condition of different content of imidacloprid in apple juices and pure apple juices respectively through fluorescence spectrometer, and the relation between their fluorescence intensity and content of imidacloprid was analyzed. The experiment results show that the most intensive fluorescence (373 nm) was found in the spectrum of imidacloprid, while the fluorescence was not found in the pure apple juices with 234 nm as the excitation wavelength. Then the imidacloprid solution was added to the fruit juices increasingly. The best prediction model was obtained for the contend of imidacloprid in the apple juices, the coefficient of determination is 0.99674, and the accuracy is higher than 90%. As a result, it is fast and feasible to carry out the detection and analysis of the pesticide residue of imidacloprid in the apple juices.