Abstract: Currently, illegal cooking oil cheating occurs constantly. It's important to search a analysis method which is fast and effective for people's table safety. In this study, near infrared spectroscopy was used to discriminate illegal cooking oil cheating. Datas of oil, which was processed with Standardization and PCA, was used for building distance analysis model and BP neural network model by metrology software. The accuracy of distance analysis was 89.71%, and BP neural network was up to 97.06%. In a conclusion, the cheating could be effectively discriminated by analyzing NIRS information.