Abstract: By developing a simulation model of hydrogen production and blending integrated system, the life cycle inventory of multi-energy flow and material flow data was established to quantitatively evaluate technical economy and carbon reduction potential of the integrated system. Based on models of levelized cost and net present value of hydrogen-doped natural gas, influences of important technical parameters including energy efficiency and current density, and economic factors including wind power prices and raw material costs, on the economic evaluation index were analyzed. The tech-economic feasibility of the integrated system was evaluated. Furthermore, a whole life cycle carbon footprint evaluation model was employed to assess the carbon reduction potential. The study shows that the prices of raw materials and electricity are the primary factors influencing the levelized cost. A decrease of 0.10 yuan/(kW·h) in wind power transaction price can result in a reduction of 149 yuan/t in the levelized cost. The proposed new reconstruction and expansion project with an annual output of 15 700 t of green hydrogen and 502 800 t of natural gas yields a net carbon emission of 27 816 t, while the total CO₂ emission from natural gas amounts to 1 334 175 t per year, considering its calorific value as hydrogen. The project is feasible in economic technology and environmental friendliness.