The applicability of galvanic-cell-based atmospheric corrosion monitoring (ACM) technology has been confirmed empirically in field tests, however the corrosion behaviors on the ACM sensors have rarely been studied systematically. In this study, the influence of temperature, chloride ions, and hydrosulfite (simulated sulfur dioxide) ions on the corrosion behaviors of Fe/Cu-type ACM sensors was investigated. The results show that the hydrosulfite ions led to a larger increase in the Fe/Cu-based ACM current than chloride ions in the initial stage of corrosion, and both changed the components of the corrosion products. Moreover, the hydrosulfite and chloride ions showed a synergistic effect on the corroded ACM sensor. Lastly, a positive correlation between ACM technology and the mass loss method was observed, further indicating that ACM technology can be an effective, convenient, and fast approach to studying the accelerated corrosion behaviors of steels.