A homemade micro-spectrometer analytical system was developed for the quantitative determination of the sorbic acid in the food based on the photometric principle. And with the standard addition method it was applied to eliminate the interference coming from the food substrate. The detecting result illustrated a good relativity in the range of 0～10.0 mg·L-1 with the linear correlation coefficient of 0.998 9, and the sample recovery was 99.2%～99.5% with RSD of 0.58%. The micro-spectrometer analysis system has shown potential prospective application in the fields of rapid and high performance detection for food additives.