The invention discloses a system and a method for producing vanadium trioxide, and belongs to the technical field of chemical industry. The system comprises a fluidized reduction furnace, a feeding system, a combustion system, a cooling system, a tail gas treatment system, and a discharging system. A heat exchange member is arranged inside the fluidized reduction furnace, and is in a U shape; the heat exchange member makes flue gas and materials exchange heat in a mode of coupling reverse flow with cross flow; the fluidized gas enters the furnace from a fluidized air inlet and the raw materials enter the furnace from a feed inlet; the fluidized gas moves from bottom to top to suspend the raw materials in the furnace body and drive the raw materials to move upwards and be discharged from a discharge hole, and the reaction tail gas is exhausted from a tail gas outlet; the heat exchange member has the functions of improving the fluidized state and exchanging heat simultaneously; and high-temperature flue gas enters the furnace from a flue gas inlet, and after heat exchange, the high-temperature flue gas is exhausted from a flue gas outlet. The system for producing the vanadium trioxide has the advantages of applicability to mass production of vanadium trioxide, good device tightness, high safety, high reaction efficiency, vanadium recovery rate of over 99.4 percent, and vanadium grade in the vanadium trioxide of 67.9 percent.