Abstract: A method for selection of a calibration set and a validation set based on spectral similarity and modeling. The method includes: performing NIR spectrometry on original samples to obtain a spectral matrix of the original samples; randomly selecting m samples as an independent test set; calculating spectral similarity between each of the samples in the independent test set and each of the remaining samples in the original samples respectively to obtain g samples having the highest similarity to be written into the validation set; and calculating spectral similarity between each of the samples in the validation set and each of the remaining samples in the original samples respectively to obtain n samples having the highest similarity to be written into the calibration set. Based on the validation set and the calibration set selected through the method, an obtained model can predict unknown samples more accurately.