In this study, the High Performance Liquid Chromatography-Evaporative Light Detection (HPLC-ELSD) was used to establish the rapid comparison and content calculation of effective components of galacto-oligosaccharides based on the fingerprint analysis. Using this method, 11 anonymous commercial food-grade galacto-oligosaccharides products were compared based on the fingerprint composition comparison and content calculation of the effective component. The results showed that the composition of the commercial food-grade galacto-oligosaccharides product composition close to each other, and the non-effective components generally included glucose, galactose and lactose constitute. The number of effective ingredient peaks was 1 to 2, and the mass concentration range was 73.65～100.00 g/100 g. It was mainly composed of a mixture of galacto-oligosaccharides with a degree of polymerization greater than 3, and the effective component in some products was exclusively iso-lactose. The establishment of this method has enabled the effective evaluation of the quality of galacto-oligosaccharides products.