A novel polygeneration system has been developed to enhance resource efficiency and reduce environmental pollution by integrating waste incineration, water electrolysis, carbon capture, ammonia, and methanol synthesis. This system enables methanol-ammonia cogeneration and achieves near-zero carbon emissions across its full life cycle. With thermal and exergy efficiencies of 56.30% and 55.17% respectively, the system offers a payback period of 4 years and a projected net present value of k$275,897.01 over a 20-year lifecycle. By directing oxygen byproduct from the alkaline electrolyzer into a waste incinerator for oxygen-enriched combustion, zero-carbon-emission green ammonia production is achieved, improving overall resource utilization. The study highlights the economic feasibility of CO2-to-methanol conversion and the potential for significant carbon emission reductions through integrated process design, emphasizing the importance of technological innovation and renewable energy in waste management and resource utilization.