A precast wall having an integrated wall structure constructed by pouring concrete between precast panels, the precast wall comprising: an outer panel and an inner panel spaced apart at a distance and facing each other; a plurality of truss connection members connecting the outer panel and the inner panel; rail members (11, 21) buried in the outer panel and the inner panel, respectively, and connected to the truss connection members; and coupling members respectively coupled to one surface of a corresponding rail member (11, 21) of the rail members (11, 21) connected to the truss connection members in a longitudinal direction, wherein the truss connection members include horizontal members spaced apart at a distance and horizontally connecting the rail members (11, 21) and inclined members respectively connecting the rail members (11, 21) in an oblique direction between one horizontal member and another horizontal member of the horizontal members, wherein the rail members (11, 21) comprise extension members (13, 23) extending in longitudinal directions and buried in the outer panel and the inner panel, a plurality of link members (15, 25) connected to the extension members (13, 23), and the link members (15, 25) have a bent shape, such that each of the truss connection members is joined to one surface of a corresponding link member (15, 25) among the link members (15, 25), characterized in that the precast wall further comprises reinforcing members (17,27) connecting the plurality of extension members to each other, and the coupling members have a structure, with both end portions being bent in the same direction, and threads being formed on the both end portions, and being coupled to one other surface of the corresponding link members (15, 25) of the link member(15, 25), to which corresponding reinforcing members(17, 27) among the plurality of reinforcing members (17, 27) are joined, by bolt-nut fastening by penetrating through the corresponding link member(15, 25) from a position opposite the truss connection members being joined to the corresponding link member (15, 25). an outer panel and an inner panel spaced apart at a distance and facing each other; a plurality of truss connection members connecting the outer panel and the inner panel; rail members (11, 21) buried in the outer panel and the inner panel, respectively, and connected to the truss connection members; and coupling members respectively coupled to one surface of a corresponding rail member (11, 21) of the rail members (11, 21) connected to the truss connection members in a longitudinal direction, wherein the truss connection members include horizontal members spaced apart at a distance and horizontally connecting the rail members (11, 21) and inclined members respectively connecting the rail members (11, 21) in an oblique direction between one horizontal member and another horizontal member of the horizontal members, wherein the rail members (11, 21) comprise extension members (13, 23) extending in longitudinal directions and buried in the outer panel and the inner panel, a plurality of link members (15, 25) connected to the extension members (13, 23), and the link members (15, 25) have a bent shape, such that each of the truss connection members is joined to one surface of a corresponding link member (15, 25) among the link members (15, 25), characterized in that the precast wall further comprises reinforcing members (17,27) connecting the plurality of extension members to each other, and the coupling members have a structure, with both end portions being bent in the same direction, and threads being formed on the both end portions, and being coupled to one other surface of the corresponding link members (15, 25) of the link member(15, 25), to which corresponding reinforcing members(17, 27) among the plurality of reinforcing members (17, 27) are joined, by bolt-nut fastening by penetrating through the corresponding link member(15, 25) from a position opposite the truss connection members being joined to the corresponding link member (15, 25).