Applying Raman spectrometry to detect several kinds of oils such as petrol, diesel oil, naphtha and KHF (aviation fuel hydro treating), the authors can explore the regular laws existing among these oils. The authors detected 150 cases of oils using Raman spectrometer developed by ourselves with 785 nm excitation wavelength miniature portable, and dealed with these spectra-paragraphs of the oils on level and SNV (normalization method) methods. The spectrograms of four categories of oils including petrol, diesel oil, naphtha and KHF and also the additives of them have different characteristics and rules. According to the alkenes peak's location and intensity we can distinguish petrol and naphtha, and then screen out some unqualified petrol. Raman spectrometry is very simple and has advantages that it needs a small amount of oil samples, at the same time, it also has no damage to test samples. The spectra-paragraphs show that different kinds of samples have different character on location and intensity of Raman peak. The Raman spectrometry method has great potential on establishing a rapid oil screening detection and identification method.