The invention discloses a unified power flow controller structure with fault current-limiting capacity. A series side converter comprises three phases of structures, wherein each phase of structure isthe same and comprises all submodules of an upper bridge arm, a near DC side reactor of the upper bridge arm, a near AC side reactor of the upper bridge arm, a near AC side reactor of a lower bridgearm, a near DC side reactor of the lower bridge arm and all submodules of the lower bridge arm, which are sequentially connected; an AC lead is arranged at the connected part of each near AC side reactor of the upper bridge arm and the corresponding near AC side reactor of the lower bridge arm; all submodules of the upper bridge arm include first to Nth submodules of the upper bridge arm, which are sequentially connected in series; an input end of the first submodule of the upper bridge arm is connected with a DC anode; all submodules of the lower bridge arm include first to Nth submodules ofthe lower bridge arm, which are sequentially connected in series; and an output end of the Nth submodule of the lower bridge arm is connected with a DC cathode. A transformer and converter devices canbe effectively protected in a grounding short circuit fault, and meanwhile, coordination of current limiting and relay protection is achieved.