Abstract: Hot-dip galvanized (HDG) steel sheets were widely used in construction, automotive, and household appliances owing to their excellent corrosion resistance. However, under elevated temperature and humidity, the zinc coating was susceptible to corrosion, forming zinc hydroxycarbonate Zn₅(CO₃)₂(OH)₆, commonly known as “white rust, ” which markedly compromised appearance and service life. Although chromate passivation could markedly enhance corrosion resistance, it relied on highly toxic hexavalent chromium (Cr(VI)), posing serious environmental and human health risks. Consequently, its use was increasingly restricted or banned worldwide. This paper provided a systematic review of recent advances in silicon-based chromium-free passivation technologies in the field of metallic corrosion protection, with a focus on the film-formation mechanisms and preparation processes of silane- and silicate-based passivation systems applied to HDG surfaces. It detailed the formation processes, structural characteristics, and protective mechanisms of silicon-based passivation layers under corrosive conditions. Furthermore, the study analyzed strategies to enhance corrosion resistance through composition design, process optimization, and composite modification. Finally, in light of the growing demand for green manufacturing and sustainable development, we discussed the potential applications and future trends of silicon-based passivation technologies for efficient and environmentally friendly metal surface protection.