Bainitic transformation goes through three stages: incubation period, nucleation, and growth. The long transformation time is not conducive to industrial production, which restricts its development. Therefore, research on accelerating bainitic transformation is based on the situation of energy saving and efficiency saving. The methods to accelerate bainitic transformation include the control of alloy elements, heat treatment control, etc. This paper focuses on the influence of the pre-formed phase on the kinetics of accelerated bainite transformation. Combined with existing research and experiments, it clarifies the influence of pre-formed ferrite, pre-formed martensite, and precipitated second-phase particles on the kinetics of bainitic transformation. Moreover, it clarifies the characteristics of bainitic transformation in terms of microstructure characterization.