The mantle velocity structure provides crucial information regarding the thermal and chemical states and tectonic evolutionary history of the Earth’s interior. The study of mantle discontinuities can provide a clearer understanding of the temperature distribution characteristics and chemical structure of the Earth’s interior. Moreover, it is important for determining geodynamic issues, such as the cause of mantle discontinuities and mantle convection models. Seismological observation data show that velocity discontinuities are commonly found at the depths of 410 and 660 km, as well as in the upper mantle (220,300-350,520,and560km) and lower mantle(800-900,1100-1200,1800,and2400km) in specific regions of the world. The topography of mantle discontinuities in different regions may be influenced by temperature, water content, mineral phase transformation, and subducting plates. The use of precursors to study mantle discontinuities has a unique advantage: Precursors arrive at the observation station earlier than the reference phase, thus avoiding the interference of other phases and detecting the weak discontinuity of the mantle more accurately. In this study, we collected and compiled research results on mantle discontinuities obtained by using precursors in recent years. The precursors used included precursors of long period reflection phases SS or PP, of deep phases sP and pP, and of the Earth surface reflection phase PKPPKP. In addition, we summarized the characteristics of different precursors and related research results of mantle discontinuities. Methods for the use of precursors to study mantle discontinuities have matured. The timely collection and summarization of relevant research results are important for understanding various scientific problems, i.e., the internal structure of the Earth, material composition of the mantle, influence of slab subduction on the mantle structure, and mantle convection mode.