The present invention discloses a flue gas low-temperature adsorption denitrification method, including: pressurizing a flue gas that has been subjected to dust removal and desulfurization, precooling the pressurized flue gas, cooling the precooled flue gas to a temperature lower than room temperature by a flue gas cooling system, flowing the flue gas at the temperature lower than room temperature into a low-temperature denitrification system, performing physical adsorption denitrification in the low-temperature denitrification system, precooling the flue gas that has been subjected to dust removal and desulfurization with the denitrificated flue gas, and flowing the heat-absorbed clean flue gas into a chimney to be discharged.