An autonomous mobile device is configured to move on a surface provided with a base station thereon, and is operated in one of a work state and return state. In the work state, the autonomous mobile device is operable to plot a movement route along which the autonomous mobile device moves, and is operable to adjust the movement route upon presence of an obstacle. In the return state, the autonomous mobile device is operable to plot a returning route on the surface from the current position to the base station, and to move along the returning route to the base station.