The invention relates to a fluidized bed reactor and a process suitable for reducing high-SO2 metallurgical flue gas to produce S. According to the technical scheme, the fluidized bed reactor mainly comprises a raw gas mixer, a pre-heater, a gas distributor, a main reaction tower body, a particle sedimentation section, a cyclone dust collector, catalyst continuous quantification equipment and a waste catalyst recovery opening, wherein the reaction temperature of the main reaction tower body is 300 DEG C to 1200 DEG C. The invention further provides a process flow for producing sulfur and the process flow mainly comprises a fluidized bed, sulfur collection, condensation and water removal and tail gas treatment, wherein the temperature of the outer part of a collection tank is controlled to be 100 DEG C to 140 DEG C; when gas is sprayed into the tank, the sulfur is crystallized and deposited instantaneously; a filtering device is additionally arranged at an outlet position. By adopting the fluidized bed reactor and the process, provided by the invention, a temperature runaway phenomenon in a sulfur production process is effectively solved and the fluidized bed reactor and the process have the advantages of great production capacity, great operation elasticity, high SO2 conversion rate, simplicity in sulfur collection and relatively high purity, simplicity and convenience for circulating a catalyst, high energy utilization rate and the like and have an excellent industrial application prospect.