The Mesoproterozoic represents a critical stage for early eukaryotic evolution. However, considerable controversy persists regarding the redox state of marine environments during this period, which significantly constrains our understanding of the environmental context for early eukaryotic evolution. In this study, a combined investigation of both macro-micro sedimentological features and major, trace elemental geochemistry of carbonate rocks of the Mesoproterozoic Wangquankou Formation from the Gan’gou section on the northern margin of the Helan Mountains is conducted. The analytical results reveal that the Wangquankou Formation exhibits a generally weak negative Ce anomaly, indicating predominantly oxic to suboxic conditions in the shallow-water tidal flat environment during this period. In the lower part of the Wangquankou Formation, the Ce/Ce* record shows a brief negative shift, decreasing rapidly from 0.83 to 0.69, and then quickly returning to ~0.85 values. In the middle part of this formation, Ce/Ce* remains relatively stable at approximately ~0.8, while toward the top, it displays rapid fluctuations, varying between 1.01 and 0.71. The composition and variation in Ce/Ce* within the Wangquankou Formation suggest that the Mesoproterozoic ocean was characterized by pulsed oxygenation and dynamic fluctuations. Furthermore, the minimum Ce/Ce* value of 0.69 observed in the Wangquankou Formation remains significantly higher than those recorded in the Phanerozoic and modern shallow marine settings, indicating that dissolved oxygen levels in the Mesoproterozoic ocean were substantially lower than those achieved in post-Proterozoic oceans. Persistent low oxygen state in shallow marine environments may have been a key factor limiting the early radiation and evolution of eukaryotic organisms. This study provides new evidence for understanding the evolution of redox conditions in the Mesoproterozoic ocean and contributes to further elucidating the co-evolutionary relationship between Earth's surface redox state and eukaryotic life during the Mesoproterozoic.