Method for eliminating high-order diffraction influence of grating spectrometer

The invention relates to a method for eliminating a high-order diffraction influence of a grating spectrometer. The method comprises a calibration process and an actual measurement process. The calibration process comprises the steps of: determining a range of a diffraction order m on an imaging sensor according to a response wavelength range of the grating spectrometer; sequentially performing calibration from the maximum diffraction order to the minimum diffraction order of m, and repeating the following steps: selecting a narrow-band light source for irradiation, so that m-order diffractionof light in a wavelength range of the narrow-band light source falls on the imaging sensor and is not overlapped with an imaging position of first-order diffraction; and respectively reading a first-order diffracted light region and a high-order diffracted light region of the imaging sensor to obtain first-order diffracted light intensity and high-order diffracted light intensity of each wavelength lambda, and calculatin