A new calibration method for Extreme Ultraviolet(EUV) monochromator was presented.By measuring the 30.38 nm and 58.43 nm lines of a standard He hollow cathode source and the reflectivity peak of a calibrated Mo/Si multilayer mirror with central wavelength of 13.90 nm,the wavelengths of Mcpherson247 EUV monochromator were calibrated.Then,the standard points on the track of monochromator was fitted to get parabolic curve by Origin.After analysing calibrated results,it shows that the measuring accuracy is 0.08 nm and the repeatability is ±0.04 nm,when the reflectivity peak of the multilayer mirror is measured using soft X-ray reflectometer with laser-produced plasma source at 12～60 nm.The main sources of measurement errors are the instability of the light source and the rotation error of the mechanism.