The invention belongs to the technical field of flue gas heat utilization and process energy saving, especially flue gas CO2 emission reduction and cyclic utilization, and relates to a method for temperature-variable humidity-variable multi-segment series gas-solid drying by utilizing industrial flue gas waste heat. Waste heat contained in flue gas with the temperature ranging from 150 DEG C to 300 DEG C is sequentially converted into power and heat energy from high to low, wherein the heat energy is needed for gas-solid drying of warm areas with the temperature ranging from 70 DEG C to 200 DEG C of a first segment and a second segment. Heat consumed by drying of the two segments is collected into second-segment dry tail gas with the temperature being 70 DEG C or above, and the heat is recycled through a method of being in direct contact with heating circulating water and is secondarily utilized for being supplied to third-segment vibration fluidization drying of a warm area with the temperature ranging from 45 DEG C to 50 DEG C. Meanwhile, the cooled and dehumidified second-segment dry tail gas is used as a drying medium of a third segment. In a temperature-variable humidity-variable multi-segment series drying process formed in this way, power is self-sufficient, the total drying vaporization amount of the three segments is larger than the maximum vaporization capacity corresponding to smoke directly cooled to be 50 DEG C, and the process is remarkably superior to a traditional gas-liquid drying method.