The invention discloses a continuous secondary flow coagulation gas-stripping fluidized bed reactor for continuously culturing aerobic granular sludge and treating sewage. A reactor main body part is composed of internal cylindrical organic glass and external cylinder organic glass, and comprises the following four areas: a coagulation area formed by internal cylindrical organic glass, a fluidization area formed between the inner wall of the external cylindrical organic glass and the outer wall of the internal cylindrical organic glass, a depression area formed through the separation of a clapboard below the fluidization area, and a separation area formed through the separation of a separation inclined plate above the fluidization area. The reactor disclosed by the invention has an integration effect; the conventional primary and secondary treatment and reinforcement can be processed in one treatment unit; the aerobic granular sludge cultured through coagulation reinforcement can be shortened more than 10 days in comparison with the convention SBR; and the continuous culture can produce the aerobic granular sludge in a large scale. Through the adoption of the continuous secondary flow coagulation gas-stripping fluidized bed reactor, the aerobic granular sludge can be continuously and quickly cultured; and meanwhile, a good sewage treatment effect is realized, the land is saved, the energy source raw material is saved, and the environmental protection is facilitated.