A coaxial dynamical system includes a motor having a transmission shaft, a dynamical transmission member rotatably connecting to the transmission shaft, and a magnetic driving mechanism connected between the transmission shaft and the dynamical transmission member. The magnetic driving mechanism includes a sleeve assembly, a sleeve fixing member, a magnetic coupler and a magnetic driver. The magnetic coupler has a first multi-pole magnet and is positioned next to the transmission shaft. The magnetic driver is fixed to the transmission shaft corresponding to the magnetic coupler and has a second multi-pole magnet with an opposite polarity relative to the first multi-pole magnet of the magnetic coupler. When the dynamical transmission member is fails, the magnetic driving mechanism is prevented from adversely affecting the normal working of the transmission shaft through the magnetic driver by disconnecting from the magnetic coupler.