Abstract: In recent years, the safe and low-carbon treatment and disposal of municipal organic solid waste, such as municipal sludge and kitchen waste, has garnered significant attention. This study establishes an accounting methodology for carbon emissions and compensation by using a medium-sized city with a population of 1 million as a case study. Theoretical carbon emission levels for collaborative treatment, traditional incineration, and landfill pathways are analyzed to determine efficient emission reduction strategies through quantifying the contributions of direct and indirect carbon emissions. The results demonstrate that collaborative treatment of municipal organic solid waste yields significantly lower carbon emissions(513 t CO₂/year) compared to traditional landfills(12973 t CO₂/year) or traditional incineration(14733 t CO₂/year). Direct carbon emissions in the collaborative disposal process account for 63%, emphasizing the importance of maximizing resource utilization through biogas production and fermentation products for effective carbon reduction. Indirect carbon emissions during incineration and landfill processes primarily stem from power consumption during incineration(68%) and deep dehydration agent usage during landfill disposal(87%), highlighting these areas as crucial focal points for reducing the overall carbon footprint. This study's findings provide valuable insights into low-carbon approaches towards treating municipal organic solid waste while aiding cities in achieving their goals of attaining carbon neutrality.