The invention discloses a low-temperature dry deep treatment system for the whole process of waste heat treatment flue gas. The system is designed according to the characteristics of waste heat treatment flue gas. unit, low temperature vulcanization-catalytic tower and other units. In the process of treatment, energy is recycled, pollutants are treated with waste, and the treatment functions are interlocking. At low temperature (250-280°C), the particulate matter, NOx, CO, and SO in the flue gas are deeply purified. 2 , VOCs, HCl, heavy metals and dioxins, with a purification rate of over 95%, meeting the requirements of ultra-low emission standards. The system has the advantages of no waste water, low energy consumption, low investment cost, stable and reliable operation, high emission reduction efficiency, simple and easy-to-control process, etc. It is suitable for advanced treatment of heat treatment flue gas such as waste incineration, pyrolysis, and gasification.