Through analyzing the SPR reflected light intensity curve of first metal film, the two peak points on the curve are used to mark angle, and the cylindrical light and CCD are utilized to establish measurement system of reflected lightintensity of angle distribution without mechanical turntable. The information between light intensity and pixel position detected by CCD is calculated to get the curve of reflected light intensity of angle distribution by computer, and the thickness of film can be obtained through matching the curve data of database. The films of common metal as Cr, Ti, Al and Ag are used to online measure by utilizing this measurement system, and the coating sequence and the corresponding online measurement range of nanometer metal films can be obtained.