Laser-induced breakdown spectroscopy (LIBS) is an effective tool for element analysis, which has the advantages of being fast, simple and real-time. It can be used for qualitative analysis and quantitative detection of various elements in solids, liquids and gases. However, the traditional LIBS and filament-induced breakdown spectroscopy (FIBS) have intensity clamping and their sensitivity is difficult to improve, which leads to certain limitations in practical application. This has become a major technical bottleneck since the invention of LIBS technology. From the perspective of excitation sources, this paper discusses the problems of LIBS and FIBS, and introduces the research progress of optimizing LIBS in recent years. The plasma grating formed by multi-beam interference is applied to LIBS. On the basis of retaining its original advantages, the plasma shielding effect and matrix effect are effectively overcome, the intensity clamping is broken, the spectral line signal is enhanced, and the detection sensitivity and quantitative analysis ability are improved. These studies will promote the practical application of LIBS technology in various fields, and also provide research ideas for the combination of femtosecond laser plasma and other technologies.