The invention relates to a segmented accurate disassembly device for a water beam and an upright column of a heating furnace and a use method of the segmented accurate disassembly device. The segmented accurate disassembly device comprises two rails which are horizontally laid on the bottom of the furnace in a length direction of the water beam; the two ends of the two rails are provided with fourwinches for providing reciprocating pull force respectively; the two rails are provided with two disassembly supporting frames in parallel in an erecting manner; each disassembly supporting frame comprises two transporting trolleys arranged on the two rails respectively, supporting frame columns arranged at the upper ends of the transporting trolleys respectively and a supporting frame beam arranged at the upper ends of the supporting frame columns; the upper end of the supporting frame beam is provided with a pair of hoisting frames in parallel; each hoisting frame is provided with a vertical downward chain-fall; and the two disassembly supporting frames are connected with each other through a connection steel wire rope between the supporting frame columns on the same side. The segmentedaccurate disassembly device provided by the invention solves the problems that during evaporation cooling modification construction of the heating furnace, due to retention of a part of heating furnace structure, large hoisting equipment such as a truss car and a crane cannot enter a hearth for water beam and upright column disassembly of an original water cooling system and a new water beam andupright column in-place mounting of an evaporation cooling system.