A multi-axial unidirectional power transmission system includes a transmission unit and a resistance unit. The transmission unit includes a first main shaft and a transmission wheel provided on the first main shaft. The resistance unit includes a second main shaft and a damping wheel mounted on the second main shaft. The two transmission wheels and the damping wheel can be placed flat on the body since they are mounted on different main shafts, thereby making the whole plane of the multi-axis unidirectional power transmission system consistent, thus achieving the effects of space saving, convenient storage and convenient transportation.