A transmission device, comprising: a continuously-variable transmission device having a driving pulley and a driven pulley; a high shift transmission pulley train having a driven pulley; an input shaft; an output shaft arranged to rotate in the same direction as the input shaft; a clutching device, located between the input shaft and the output shaft; wherein, when rotational speed of the output shaft reaches or exceeds a predetermined rotational speed, the clutching device is closed to connect the driven pulley of the high shift transmission pulley train and the output shaft; characterized by: a torque limiting clutching device is a sliding type or a clutching type clutching device which slides or releases at a predetermined value of torque difference, installed between the driven pulley of the continuously-variable transmission device and the output shaft, or between the driving pulley of the continuously-variable transmission device and the input shaft; wherein, when there is a rotational speed difference causing the torque difference to exceed its predetermined value between the output shaft and the driven pulley of the continuously-variable transmission device, or between the input shaft and the driving pulley of the continuously-variable transmission device, said torque limiting clutching device is slid or released. a continuously-variable transmission device having a driving pulley and a driven pulley; a high shift transmission pulley train having a driven pulley; an input shaft; an output shaft arranged to rotate in the same direction as the input shaft; a clutching device, located between the input shaft and the output shaft; wherein, when rotational speed of the output shaft reaches or exceeds a predetermined rotational speed, the clutching device is closed to connect the driven pulley of the high shift transmission pulley train and the output shaft; characterized by: a torque limiting clutching device is a sliding type or a clutching type clutching device which slides or releases at a predetermined value of torque difference, installed between the driven pulley of the continuously-variable transmission device and the output shaft, or between the driving pulley of the continuously-variable transmission device and the input shaft; wherein, when there is a rotational speed difference causing the torque difference to exceed its predetermined value between the output shaft and the driven pulley of the continuously-variable transmission device, or between the input shaft and the driving pulley of the continuously-variable transmission device, said torque limiting clutching device is slid or released. a torque limiting clutching device is a sliding type or a clutching type clutching device which slides or releases at a predetermined value of torque difference, installed between the driven pulley of the continuously-variable transmission device and the output shaft, or between the driving pulley of the continuously-variable transmission device and the input shaft; wherein, when there is a rotational speed difference causing the torque difference to exceed its predetermined value between the output shaft and the driven pulley of the continuously-variable transmission device, or between the input shaft and the driving pulley of the continuously-variable transmission device, said torque limiting clutching device is slid or released.