Abstract: A magnetic-loaded exercise bicycle comprises a bicycle frame, a flywheel, a magnetic loading device, and a pedal device, wherein the flywheel is mounted on one side of the bicycle frame and the magnetic loading device is mounted on the bicycle frame inside the flywheel. When the rotatory arm is rotated, the hook is shifted within the arc-shaped trench of the fixing plate such that the distance between the magnets and the flywheel can be adjusted by shifting the rotatory arm, thereby adjusting the magnitude of the magnetic control force for increasing or reducing the loading of the flywheel. As a result, the magnetic-loaded exercise bicycle has simple structure, accurate loading, and easy maintenance.