The disclosure provides a method for removing background from a spectrogram, including: finding out peak information of a raw spectrogram, the peak information including a peak position, a starting point, an ending point, and a peak width w of a peak; processing, within each peak area defined by the starting point and the ending point of each peak of the raw spectrogram, each peak of the raw spectrogram by using a SNIP method so as to obtain background data within each peak area; replacing, within each peak area, data of the raw spectrogram with the background data obtained through processing by using the SNIP method, so as to form a background spectrogram in a fitting way; smoothing the formed background spectrogram; and subtracting the smoothed background spectrogram from the raw spectrogram so as to obtain a spectrogram with removed background.