Mixed fluidized bed reactor and application thereof

A mixed fluidized bed reactor comprises a tank body, a packing component, a first guide plate and a second guide plate, wherein the tank body is provided with a water inlet and a water outlet, the water inlet is located at the bottom end of the tank body, the water outlet is located on the side face of the tank body, the packing component is located above the water inlet, the first guide plate is located above the packing component; the second guide plate is located above the first guide plate, the lower end of the second guide plate is located in the tank body, and the upper end of the second guide plate is higher than the water outlet; the packing component comprises a screen and a guide cylinder, the screen and the guide cylinder are both of a hollow columnar structure, the guide cylinder is located in the screen, an annular containing cavity is formed between the screen and the guide cylinder, and a carrier is contained in the annular containing cavity. Application of the mixed fluid bed reactor is provid