The oil contained in wastewater has fluorescence characteristics. The fluorescence characteristics of import and export oily wastewater samples from Daqing Oil Production Plant 13 #, Daqing Chemical Plant and Petrochemical Refineries were investigated by the fluorescence analysis. Synchronous fluorescence spectroscopies of oily wastewater were obtained. The results show that, by selecting the wavelength difference Δλ=40 nm, 60 nm and 80 nm, refinery oily sewage of the oil production plant in Daqing, Daqing Chemical and Petrochemical from import and export can be distinguished from each other. When Δλ changes in the synchronous spectrum of the same concentration of the oil solution, the spectral shape, number and peak position change. Synchronous fluorescence spectrum of wastewater from the import and export of the same industry have large differences.