The invention discloses a traction machine with an adjustable driven wheel. The traction machine comprises a traction machine frame, wherein a driving motor is arranged in the middle of the traction machine frame, a front plate of the traction machine frame is provided with a mounting hole, a first adjusting groove and a second adjusting groove, the center of the mounting hole and the center of the first adjusting groove are located on the same horizontal line, the second adjusting groove is located above the mounting hole and the first adjusting groove, a driving shaft is arranged in the mounting hole, a driving wheel is installed at the front end of the driving shaft, a first connecting rod sleeves the middle end of the driving shaft, the rear end of the driving shaft is connected with adriving motor, a first sliding block is arranged in the first adjusting groove, a driven shaft is arranged in the second adjusting groove, the driven wheel is installed at the front end of the drivenshaft, a second sliding block sleeves the middle end of the driven shaft, the rear end of the driven shaft is provided with a second connecting rod, and the first connecting rod and the second connecting rod are hinged to the first sliding block. The installing distance between the driven wheel and the driving wheel is adjusted, so that the tension of a cable is adjusted, and the traction effectof the traction machine is improved.