Abstract: Sludge treatment and disposal, alongside carbon emission control, present dual challenges for the current wastewater treatment industry. This study proposes coupling sludge chemical looping gasification （CLG） technology into municipal wastewater treatment processes, systematically evaluating the entire procedure from the reaction kinetics of sludge chemical looping conversion to the carbon reduction potential of the wastewater treatment plant （WWTP）. Taking sludge from a WWTP in Qingdao as the research subject, iron-based oxygen carriers （Fe/Mg-Al and Fe−Ni/Mg-Al） were synthesized via the sol-gel method. Additionally, red mud, an industrial solid waste, was selected as a reference oxygen carrier to investigate the regulatory mechanisms of different oxygen carriers on sludge gasification reaction kinetics and syngas quality. Based on the actual operational data of the plant, a life cycle assessment （LCA） approach was employed to evaluate the carbon mitigation benefits of substituting the existing anaerobic digestion technology with sludge CLG. The results indicate that the introduction of oxygen carriers slightly increased the activation energy of the sludge CLG reaction （from 119.68 kJ/mol to 121.16–122.60 kJ/mol） due to solid-solid reaction limitations and ash interactions. However, the pre-exponential factor was significantly enhanced via the kinetic compensation effect, thereby maintaining the overall reaction rate. Leveraging the synergistic effect of lattice oxygen oxidation and the catalytic properties of inherent alkali metals （e.g., Na and K）, the red mud oxygen carrier exhibited optimal hydrogen production performance. The heating value of the syngas was elevated from 2.67 MJ/m³ （pure sludge gasification） to 5.50 MJ/m³, while effectively preventing the deep oxidation issues typically associated with nickel-based oxygen carriers. The LCA results demonstrated that introducing the sludge CLG technology could shift the global warming potential （GWP） of the WWTP from 2.80 kg under the traditional anaerobic digestion process to −8.44 kg, successfully achieving a negative carbon emission operation. Notably, the exothermic heat from the CLG reaction and the combined heat and power （CHP） generation from the syngas were identified as the primary sources of carbon mitigation, contributing 45.2% and 125.3% to the total carbon emission reduction, respectively. Furthermore, this technology significantly mitigated other environmental impact indicators through energy recovery and heavy metal immobilization.