Abstract: The efficient recovery of waste heat from flue gas of industrial coal-fired boilers is of great significance for improving energy efficiency. In view of the problems of corrosion, scaling and heat transfer efficiency attenuation of traditional metal heat exchangers, the use of modified fluoroplastic heat exchanger technology is proposed to achieve deep recovery of waste heat through material property optimization and structural innovation. Based on the engineering practice of two 20 t/h coal-fired boilers in an enterprise, the heat transfer mechanism, economic performance and environmental benefits of modified fluorinated plastic heat exchangers were systematically analyzed. The research shows that the modified fluorine plastics can effectively solve the corrosion failure problem of metal materials in acidic wet flue gas environment with excellent chemical stability （annual corrosion rate is only 0.02 mm） and surface characteristics （friction coefficient is as low as 0.1–0.2）. Through the dense arrangement design of thin wall small pipe diameter （pipe diameter 10 mm, wall thickness 0.6 mm）, the total heat transfer coefficient of the material is comparable to that of the metal heat exchanger under the condition of the thermal conductivity of the material is only 0.48 W/（m·K）, which is because the heat exchange area per unit volume is 3–4 times higher than that of the metal material. Engineering application data show that the system can reduce the flue gas temperature from 150 °C to 90 °C, the circulating water temperature from 35 °C to 67 °C, the annual recovery of heat equivalent to 12744 tons of standard coal, equivalent to 14400 tons of steam. The economic analysis shows that the total investment of the project is 1.5 million yuan, and the investment payback period is 6–9 months through steam recovery and coal saving, and the annual economic benefit is more than 2.9 million yuan. Significant environmental benefits, annual emission reduction of 33395 tons of CO₂, 108 tons of SO₂, 94 tons of NO_x. The study confirmed that the use of modular design and mechanical booster connection technology, through indirect heating to maintain 0.8 MPa safe working pressure, equipment service life of up to 20 years, maintenance costs reduced by more than 70%. The application of modified fluoroplastic heat exchanger in flue gas waste heat recovery system has good feasibility, can effectively save energy and bring significant economic and environmental benefits.