Quantitative detection of oil slick thickness in the ocean is an essential basis to achieve an accurate estimate of oil spills and provides primary data for the development of oil pollution emergency response. In this paper, we use diesel(0# diesel), motor oil (Mobil motor oil 20w-40), Lubricants (Shell Helix 15w-40, Shell Helix 10w-40, Shell Helix 5w-40) as the research objects, using laser-induced fluorescence (LIF) obtains the spectra of materials. The oil film thickness-fluorescence intensity calibration curves are established, and the detection limits of five kinds of oils are calculated. The accuracy of the quantitative detection of different oil film thicknesses in different water is analyzed. The results show that the fluorescence spectra of 0# diesel and Mobil motor oil 20w-40 are significantly different from those lubricants. The fluorescence peak of diesel is at 326 nm, and its FWHM is 60 nm. Mobil motor oil 20w-40 has three fluorescence peaks at 360 nm/375 nm/390 nm, and the FWHM is about 100 nm. The fluorescence spectra of the three lubricants (such as Shell Helix 15w-40, Shell Helix 10w-40, Shell Helix 5w-40) overlap significantly, and the fluorescence peaks are located at 334, 344, and 343 nm, respectively. With the increase of oil slick thickness, the fluorescence intensity of the five kinds of oil films is rising. The calibration curves of oil slicks have good correlation, and the correlation coefficients(r) are 0.997 8, 0.997 9, 0.996 4, 0.997 8, and 0.996 0, respectively. The detection limits are 0.03, 0.02, 0.02, 0.03 and 0.05 μm. It can be seen that the average relative errors of quantitative detection of five kinds of oil films in different water are less than 14%, and the average relative standard deviations are not greater than 10%. The results can be used to measure thin oil films and provide a technical means for on-line monitoring of oil film thickness at sea.