Due to unreasonable arrangement of flue behind induced draft fan (IDF), there are some problems in terms of a flow resistance increase and a desulfurization efficiency decrease. According to the phenomenon of compact arrangement of boiler tail section and flow breakdown of conflux flue behind IDF in a power plant of Sinkiang, the conflux flue behind IDF was numerically simulated by computational fluid dynamics (CFD), and some splitters were used for flow field optimization with good effect.