Speed regulation winch controlled by PLC and speed regulation method

The invention discloses a speed regulation winch controlled by a PLC and a speed regulation method. The speed regulation winch comprises a mounting frame, the bottom end of the mounting frame is connected with two side supports, a rolling shaft is arranged between the two side supports, a driving mechanism is arranged on one side of one side support, the driving mechanism is covered with a heat dissipation mechanism, and a weight measuring mechanism is arranged on the rolling shaft and the mounting frame; the driving mechanism comprises a first fulcrum shaft, the first fulcrum shaft is connected with the rolling shaft through a weight measuring mechanism, a plurality of first gears are arranged on the first fulcrum shaft, the distances between the first gears are consistent, the first gears are arranged according to the large diameter, the small diameter and the medium diameter, and the first gears are engaged with a plurality of second gears correspondingly; the speed regulation winch controlled by the PLC a