The continuous and slow release of Cr(VI) from chromium ore processing residue contaminated soil (COPR-soil) poses a substantial threat to soil and groundwater. Despite microbial reduction is considered as an effective approach for the remediation of Cr(VI)-contaminated soil, the efficiency and rate of Cr(VI) reduction in COPR-soil, especially Cr(VI) embedded in minerals (e.g., vaterite, Ca/Al-Cr layered double hydroxide (Ca/Al-Cr LDH)) remain low. Here, a biostimulation-enhanced microbial detoxification strategy was developed, utilizing the strong electron transfer properties of FeS