The invention discloses a method for preventing a main flue and a dust remover in circulation sintering from condensation. The method comprises the steps that firstly, the part from the head to the tail of a sintering machine is divided into three sectors in the walking direction of a trolley, wherein the three sectors account for 5-15 percent, 55-70 percent and 20-35 percent of the length of the sintering machine respectively; secondly, when the circulation sintering is carried out, sintering flue gas is extracted from the first sector and the third sector to enter a circulation flue gas channel (7), the flue gas, with dust removed, entering the circulation flue gas channel is mixed with the exhaust gas of a ring cooler and air or oxygen to be conveyed to the material face of the sintering machine to serve as sintering process gas, the sintering flue gas in the second sector and the sintering flue gas, not entering the circulation flue gas channel, in the first sector and the third sector enter a main flue (8), and the flowing direction of the flue gas in the circulation flue gas channel and the flowing section off the flue gas in the main flue are the same; thirdly, air bellow branch pipe devices located in the first sector and the third sector are adjustable in flue gas flow and flowing direction; fourthly, the main flue and the circulation flue gas channel are located in the same flue gas master pipe.