A barrier structure for a cargo hold corner, comprising: at least one lower corner insulation board including a first corner insulation board and a second corner insulation board each manufactured to be separated as a single body and installed at a corner of a cargo hold, each of the first corner insulation board and the second corner insulation board is provided with inner holes in which stud bolts are inserted that are vertically fixed to an inner hull wall of the corner of the cargo hold thereby fixing the lower corner insulation board to said inner hull wall and includes a lower protective plate, a lower insulation member, and a lower auxiliary panel stacked one on top of another, wherein an incline of the second corner insulation board is attached to an incline of one side of the first corner insulation board to form an interface therebetween; a second curved barrier having opposite side ends coupled to an upper side of the first corner insulation board and an upper side of the second corner insulation board, respectively, through a fastening member such that a curved corner of the second curved barrier is disposed around the interface; a second flat barrier disposed over both the lower corner insulation board and a lower flat insulation board installed on a flat part of the cargo hold such that the second flat barrier is connected to the second curved barrier; an upper corner insulation board disposed on an upper side of the second curved barrier to correspond to the lower corner insulation board and including an upper auxiliary panel, an upper insulation member, and an upper protective plate stacked one on top of another; a fixing piece inserted into an upper groove of the lower auxiliary panel and coupled through a fastening member; a coupling bolt vertically coupled to a coupling groove of the fixing piece to protrude toward an inner hole of the upper corner insulation board through a through hole of the second flat barrier; and a fastening unit coupled to the coupling bolt. at least one lower corner insulation board including a first corner insulation board and a second corner insulation board each manufactured to be separated as a single body and installed at a corner of a cargo hold, each of the first corner insulation board and the second corner insulation board is provided with inner holes in which stud bolts are inserted that are vertically fixed to an inner hull wall of the corner of the cargo hold thereby fixing the lower corner insulation board to said inner hull wall and includes a lower protective plate, a lower insulation member, and a lower auxiliary panel stacked one on top of another, wherein an incline of the second corner insulation board is attached to an incline of one side of the first corner insulation board to form an interface therebetween; a second curved barrier having opposite side ends coupled to an upper side of the first corner insulation board and an upper side of the second corner insulation board, respectively, through a fastening member such that a curved corner of the second curved barrier is disposed around the interface; a second flat barrier disposed over both the lower corner insulation board and a lower flat insulation board installed on a flat part of the cargo hold such that the second flat barrier is connected to the second curved barrier; an upper corner insulation board disposed on an upper side of the second curved barrier to correspond to the lower corner insulation board and including an upper auxiliary panel, an upper insulation member, and an upper protective plate stacked one on top of another; a fixing piece inserted into an upper groove of the lower auxiliary panel and coupled through a fastening member; a coupling bolt vertically coupled to a coupling groove of the fixing piece to protrude toward an inner hole of the upper corner insulation board through a through hole of the second flat barrier; and a fastening unit coupled to the coupling bolt.