Under the background of the "dual-carbon" strategy, the efficient resource utilization and carbon emission reduction in wastewater treatment plants have become crucial issues that need to be addressed urgently. This study is based on the AB process, adopting a method that combines sludge anaerobic digestion with combined heat and power generation. Taking a wastewater treatment plant with a scale of 20×10⁴ m³/d in the northwest region of China as the research object, and using the quality standard for farmland irrigation water as the standard for reclaimed water utilization, the carbon emissions and carbon emission reduction of the plant are calculated in detail. The research shows that through the utilization of wastewater resources, carbon emissions can be effectively reduced by approximately 3.5×10⁴kgCO_-eq?/d . Combining sludge biogas power generation, boiler heating, and land use, the carbon emission reduction rate of this plant can reach 42.28% . In addition, by using biogas for power generation and heating through combined heat and power generation, the energy neutralization rate of the wastewater treatment plant can be increased to 37.72% . Finally, based on the analysis of the accounting results, key measures for carbon emission reduction in wastewater treatment plants were proposed.