This work uses diffuse reflectance spectrum of NIR as sample to study the qualitative analysis of jujube, and classify infested and intact jujubes. The effects of different spectral pretreatment methods on the results of spectral analysis are studied. The results show that the combination of wavelet transform and derivative can effectively improve the accuracy of the near-infrared spectrum. The correctness of classification of original spectrum is 87.08%, after data pretreatment in both calibration and prediction set. So the wavelet transform differential modeling result is best the accuracy is 96.67%. NIR is illustrated could be applied to classify jujubes.