Abstract: To address the issues of iron phase enrichment, rapid cycle performance degradation, and the difficulty in balancing stability and low cost associated with Fe/Al oxygen carriers (OCs) in sludge chemical looping gasification (CLG), this study investigates the feasibility of using iron-rich sludge ash (IRSA) as an OC in municipal sludge CLG. Subsequently, the synergistic oxygen-carrying characteristics of IRSA and Fe/Al OCs are explored. Six cyclic experiments of sludge gasification-OC regeneration were conducted in a bubbling fluidized bed reactor using IRSA, Fe/Al OC, and their equal-ratio mixtures. Gas quality, structural evolution of the OC, and coking behavior were analyzed using gas chromatography, XRD, SEM, BET, and TGA. Results indicate: Fe1Ash1 exhibits optimal catalytic sludge gasification performance, with corresponding syngas calorific value stabilizing at 16 - 19 MJ/m3, significantly reduced CO? content, and enhanced H? and CO selectivity, demonstrating excellent partial oxidation and reforming catalytic functions; XRD and SEM analyses revealed that the sludge ash mixture suppressed Fe species migration and agglomeration and Fe2C formation, mitigating structural sintering of the OC.