Based on the composition of Tianjin municipal solid waste (MSW) and its content, collaborative emission reductions of three main MSW disposal ways were analyzed, including landfill with landfill gas burned (S1), landfill with landfill gas utilized (S2), and incineration with electricity (S3). Taking Tianjin Binhai municipal solid waste incineration power generation CDM project and Tianjin Shuangkou landfill gas recovery and electricity generation CDM project as examples, the calculation methods provided by Intergovernmental Panel on Climate Change (IPCC) Guidelines were used to calculate the greenhouse gas emissions and emission reductions, and then the collaborative emission reductions of the three scenarios were compared. Results show that the collaborative emission reductions of S1S3 are 0.602 t CO_2e/t MSW, 0.657 t CO_2e/t MSW, and 0.777 t CO_2e/t MSW respectively, so the comparison results is S3>S2>S1.