The invention discloses a modular numerical control rebar and steel wire straightening and cutting device. The device comprises a steel wire and rebar placing frame, a split type traction mechanism ora centralized traction mechanism, a transverse straightening mechanism, a longitudinal straightening mechanism, a swing type cutting-off mechanism or a flying shear type cutting-off mechanism, and each mechanism is fixedly connected with a bottom frame in a threaded manner, so that too large shaking is prevented. During working, steel wires and rebar are placed on the placing frame in advance, the steel wires and the rebar are driven to move through the power of the traction mechanism, traction of the traction mechanism can drive the steel wires and the rebar to enter the straightening mechanisms and then enter a cutting area, so that straightening and cutting are completed correspondingly. The device is easy to assemble and disassemble, is flexible and changeable, and can realize modularization.