Abstract: Objective To develop a simple, quick, and accurate detection method for distinguishing hogwash oil from raw vegetable. Methods Testing samples included 106 raw vegetable oils in 10 categories and 11 batches of refined hogwash oils. The Raman spectra were scanned to compare the morphology and acquire the first derivatives, including the lower limit value for each kind of raw vegetable oils to establish steps of the method. The accuracy was evaluated by detecting 234 mixture samples. Results There was morphology of smooth bulk peak in all refined hogwash oils, and the 2 839 cm-1 peak values were negative for the first derivatives. The ratios of peak 2 944 to 2 839 cm-1 were between -0.851 and -3.015. The accuracies for the mixtures with 10% and 20% hogwash oil were 80% and 100%, respectively. ConclusionRaman spectra of hogwash oil and raw plant oil were significantly different and can be used as reference for distinguishing between them.