To actively respond to the dual carbon target and promote the development of renewable energy and coal complementary power generation technology, a coupled heating system of coal power generation and garbage power generation was proposed. Part of the heating exhaust steam of the coal-fired power unit is used to draw all the exhaust steam of the waste power unit through the extractor. After mixing, the water in the heat network is heated once. Through the spike heater, the heating extraction steam of the coal-fired unit is used to heat the heat network water again, so that it reaches the prescribed water supply temperature of the heat network. Through the system integration, the cold end loss of the heating extraction steam of the coal-fired unit and the waste generator unit can be effectively reduced, thus improving the overall efficiency of the system. A 660 MW coal-fired unit and a waste generating unit with a waste disposal capacity of 20.8 t/h were selected as the research objects, the simulation calculation was carried out through the EBSILON software and the detailed thermodynamic and economic analysis were carried out. The results show that when the electric power of the coal-fired unit is 495.00 MW (75% THA) and the garbage generator is 9.52 MW(100% THA), the exhaust steam loss of the garbage generator in the coupled system is reduced, the heating efficiency is increased by 0.16%, the power generation efficiency is increased by 0.52%, and the system coal consumption is reduced by 1.65 t/h (measured by standard coal). The energy-saving effect is significant. The exergy loss of the peak heater in the thermal grid is reduced by 6.06 MW and that of the waste generator is reduced by 2.04 MW. The reason for the efficiency improvement of the coupled heating system is the reduction of exergy loss of the heater in the thermal grid. After the heating renovation, the new equipment investment is 4.957 million yuan, the annual operation and maintenance cost is 198 300 yuan, and the system energy saving benefit is 5.429 2 million yuan. The final annualized new net income is 4.239 5 million yuan, which has a good economic benefit.