Fluidized bed reactor

The invention discloses a fluidized bed reactor. The inner space of the main body of the fluidized bed reactor comprises a settlement zone and a reaction zone from top to bottom. An inclined separation body is hermetically arranged in the settlement zone and divides the settlement zone into an upper chamber and a lower chamber. The upper chamber is provided with a gas outlet. A gas-solid separation device is arranged in the lower chamber. A gas-solid mixed phase inlet section and a particle outlet section of the gas-solid separation device are located in the lower chamber. An exhaust pipe of the gas-solid separation device passes is communicated with the upper chamber through a gas delivery pipe passing through the separation body. The upper chamber is communicated with a return pipe which passes through the separation body and can stretch into a dense bed. The fluidized bed reactor can timely convey separated fine catalyst particles into the dense bed of the reactor so that the amount of the suspended cataly