The invention discloses an integral fast-assembly type steel-structure elevator. The integral fast-assembly type steel-structure elevator is composed of a first-segment modular section, a middle modular section and a top modular section, wherein the first-segment modular section is composed of a first-segment frame, a first main guide rail support, a first shared guide rail support, a first main guide rail, a first counterweight guide rail, a lift car fixing frame support, first-segment frame stand columns, a lift car assembly, a first landing door system, lift car fixing frames, first-segment frame cross beams and first outer decorations; the middle modular section is composed of a middle frame, a second main guide rail support, a second shared guide rail support, a second main guide rail, a second counterweight guide rail, a second landing door system, a middle frame cross beam and second outer decorations; and the top modular section is composed of a top frame, a third main guide rail support, a third shared guide rail support, a third main guide rail, a third counterweight guide rail, a traction machine beam, a traction machine, a counterweight frame, a third landing door system, a counterweight frame fixing frame, a top frame cross beam and third outer decorations. According to the integral fast-assembly type steel-structure elevator, the three modular sections are assembled in a factory, so that the on-site construction time is greatly saved, and small influence is caused to the outgoing and life of residents.