The physicochemical property and tribological lubrication characteristics of naphthenic base oils were studied.Two kinds of metalworking fluids of microemulsion and cutting oils were prepared by using naphthenic base oils,which performance was analyzed.The results show that due to high content of cycloalkanes,naphthenic base oils own the characteristics of low viscosity index and pour point,high volatility and density,and they are very suitable for application in metalworking fluids.The developed naphthenic base cutting oil has good lubrication and cooling performance,and low tapping torque.The particle size distribution of microemulsion fluid prepared by naphthenic base oils is uniform and concentrated,and the stability of the product original solution and working fluid is excellent.