Glycomics research plays an important role in life sciences and biomedicine industry. Oligosaccharide structure identification is one of the important research topics of glycomics. The development of high-throughput mass spectrometry technology in recent decade contributes significantly to oligosaccharide structure identification. In this review, we introduced the research background of tandem mass spectrometry assisted glycan structure identification. Then, we reviewed the current strategies used for glycan identification and analyzed the key technologies of existing methods. Finally, we summarized the advantages and disadvantages of the existing methods. The outlook on utilization of tandem mass spectrometry to assist oligosaccharide structure identification is also discussed.