Flywheel elliptical machine is a very common cardio-pulmonary training tool in general fitness clubs, and it is also widely loved by users. Its sports form is similar to cross-country skiing. In the research and development of flywheel elliptical machine, the dynamics of direct drive system is adopted, which can provide the most stable motion on the flywheel elliptical machine. The flywheel and the crank are installed on the same drive shaft, and are directly driven by the pedal through the patented transmission system, so that the inertia generated by the flywheel is continuously connected to the pedal, which provides a smooth feeling as much as possible when stepping forward and backward. Combined with the precise weight balance, pedal, handle and pedal angle and step frequency of the direct drive system, it provides a perfect movement mode and ensures consistency. This movement creates a "floating" effect. Once it reaches a certain speed, it can begin to "float" and feel the smoothest movement on the flywheel elliptical machine.