In order to enrich the life of the crew at sea, an immersive synchronous roaming system is researched and designed. Thus, the crew can interact with the video scenes while running, and connect the realistic 3D images to the living environment around sea and dock. The system is a perfect combination of 3D video playing and treadmills that the speed of video playing changes synchronously with that of the experiencer. After wearing 3D glasses, the experiencer can roam as if he was in the real scene. This system can help the crew adjust mood effectively, release psychological pressure and improve physical fitness.