A non-motorized treadmill includes a non-motorized treadmill body and a composite resistance module. The non-motorized treadmill body includes two rollers and a treadmill belt. The treadmill belt is wound around the two rollers. The composite resistance module includes a reluctance module and a fan wheel. The reluctance module includes a wheel body and a resistance member. The wheel body is mounted to one of the rollers. The resistance member is located close to the wheel body. One of the wheel body and the resistance member includes a metal member. The other of the wheel body and the resistance member includes a magnetic member. The fan wheel is connected to one side of the wheel body so that one of the rollers is subjected to magnetic resistance and wind resistance when rotated.