The invention discloses a Raman spectroscopy for quick field detection for melamine in liquid milk. A liquid milk sample is diluted by water or a water solution with a pH value of between 2 and 14 in 1 to 10 times of dilution proportion and then is centrifugated; an uniform test solution of an intermediate layer after the centrifugation is drawn into a detection cell with a volume of 2ml which ispre-added with a detection reagent to be vortexed or shaken evenly; the detection cell is placed in a portable Raman spectrometer detection cell and is scanned and detected by a Raman spectrum withinthe range of between 250 and 2,300cm<-1> to obtain a Raman spectrogram; a Raman spectrum signal of the melamine under characteristic frequency is selected according to the obtained Raman spectrogram;a normalization method is adopted by taking an internal standard signal as a reference, and the quick field quantificational and qualitative detection is performed on the melamine in the liquid milk sample according to a liner proportion relation between the relative intensity of the Raman spectrum signal of the melamine and the content of the melamine. The method has simple pre-treatment of the sample, can realize accurately qualitative and quantificational analysis, has low cost of experimental consumptive materials, can perform quick field detection, and is easy to popularize and promote.