The invention belongs the field of biochemical analysis, and discloses a method for increasing oligosaccharide ionization efficiency, and relates to a method for increasing oligosaccharides ionization in a matrix auxiliary laser desorption flight time mass spectrum (MALDI-TOF MS). The method employs 6-HYNIC as matrix analysis oligosaccharides, and optionally increases the ionization efficiency of oligosaccharide, and inhibits ionization of other analyte such as a peptide segment. The 6-HYNIC has a structure shown in a formula (I); the 6-HYNIC as the matrix for analysis of oligosaccharide has the advantages of high sensitivity, uniform crystallization, strong salt resistance performance, and abundant tandem mass spectrometry fragment information. The method employs 6-HYNIC as the matrix for analysis of oligosaccharide, and optionally increases the ionization efficiency of oligosaccharide, and inhibits ionization of other analyte such as a peptide segment. The method has the advantages of simple operation, simple steps, economy, time saving, and no requirement of salt removal.