Abstract: Relying on the high level of integration, cost-effectiveness, and compatibility with digital integrated circuits, silicon-based integrated millimeter-wave terahertz sources have become indispensable for applications such as next-generation 6 G high-speed communications, high-precision situational awareness radar, and ultra-high-resolution imaging. This paper investigates and summarizes the progress of domestic and international research on key nonlinear circuit frequency multipliers. It provides a comprehensive overview of topological classifications and applicable scenarios of silicon-based millimeter-wave terahertz frequency multipliers. Furthermore, recent advancements in transistor nonlinear theory applied to optimize harmonic generation are discussed. Finally, an outlook is provided for the future development of silicon-based millimeter-wave terahertz frequency multipliers along with a clear research roadmap for related researchers.