The invention discloses a NIR method for fatty acid content of oilseeds, including: selection of oilseed samples, and analyzing the oilseed samples by an near infrared spectrometer to obtain NIR spectra; preprocessing of NIR spectra and establishment of a NIR spectral database of oilseeds; establishment of a fatty acid database of oilseeds based on gas chromatography; establishment of prediction model of fatty acids in oilseeds; acquiring NIR spectrum of a sample to be tested by the near infrared spectrometer, and importing the preprocessed NIR spectrum into the prediction model of fatty acids to obtain the predicted fatty acid content of the tested sample. The method is simple and rapid to operate and is non-destructive, and the detection time of the sample is greatly shortened and the detection cost is reduced.