Seagrasses are the only higher angiosperms fully living in marine environments, which have important ecosystem service functions and enormous economic value. However, in recent years, the structure and function of seagrass ecosystems have been threatened by multiple global stressors caused by human activities and climate change, resulting in the continuous degradation of seagrasses. The stability and resilience of the seagrass ecosystem under external stress depend highly on its sexual reproduction, i.e., seed reproduction. When stressors cause irreversible damage to seagrasses, population maintenance and self-renewal could occur through sediment seed banks. Therefore, it is crucial to study the dispersal processes of seeds and the mechanism of seed bank formation, which play a key role in maintaining seagrass ecosystem stability. This paper reviews the life-history types, seed reproductive characteristics, seed dispersal processes and their influencing factors and seed bank formation of seagrass. On the basis of these understandings, we further proposed that future studies should focus on: 1) sexual reproductive efforts of seagrass under different environmental stress conditions; 2) the influencing factors and mechanism of secondary dispersal of seagrass seeds; 3) the influence of sediment deposition and resuspension on seed dispersal and retention processes; 4) prediction and simulation of the potential distribution of seagrasses and suitable habitat of seed bank under changing environments. This study is expected to provide theoretical references for the protection and restoration of seagrass meadow ecosystems.