The invention discloses a line-straightening machine, which comprises a transmission device and a cutting device, wherein the transmission device comprises a main frame; the front and rear sides of the main frame are both provided with a first baffle plate and a second baffle plate leftwards and rightwards; an electrical cabinet is connected to the front of the second baffle plate on the front side of the main frame; a first motor and a transmission mechanism are arranged in the main frame; two line feeding devices are arranged in a way of running through the front and rear parts of the main frame respectively; the rear end of each line feeding device is connected with a chain group, while a right end is provided with an oil groove; a rotating shaft mechanism is arranged between the two line feeding devices; a protective cover is arranged above the rotating shaft mechanism; a vertical frame is arranged above the right end of the main frame; a second motor is arranged above the vertical frame, and is connected with a belt pulley group through a belt; the cutting device comprises a lower bracket; and the lower bracket is connected with a movable rod, an annular frame and a short hopper, and is connected with a discharge mechanism through the movable rod. The line-straightening machine has the advantages of capability of cutting different metal wire lengths, good straightening effect, manufacturing cost reduction and high practicability.