A back-scattering fluorescence spectrum technique for recognition of petroleum and lubricant is developed by use of 532 nm exciting wavelength laser. It is shown that the ratio of back-scattering fluorescence intensity to the scattered main laser intensity depends strongly on the oil type and the incident angle. To enhance the feature of oil type, the ratio data of 45° and 60° incidence are fused in a 2D spectrum. Then the 2D spectrum is divided into two areas, the oil type can be determined according to which area the measured ratio data lie in. The experimental results show that the correct identification probability can be as high as 92%. It is expected that the proposed method can be a useful technique for oil type recognition.