The invention relates to an automatic portable floating sludge removing device as well as the installation and using methods thereof. The portable floating sludge removing device comprises a buoyant ring floating on the surface of a water pool, a floating sludge collection device arranged below the surface in the water pool, an adjustable rope for connecting the buoyant ring and the floating sludge collection device and a sludge drainage device arranged below the floating sludge collection device, wherein the floating sludge collection device comprises a floating sludge collector with a sludge drainage hole, a fully sealed cavity floating ball connected and arranged below the floating sludge collector, a first sludge drainage pipe arranged in the fully sealed cavity floating ball in a penetrating manner and a balancing weight arranged at the bottom of the first sludge drainage pipe; the buoyant ring is a plastic body of a hollow ring shape and made of polystyrene foaming materials; an antibacterial film is additionally arranged at the outer surface of the buoyant ring. The device is simple in structure, scientific in design, suitable for various kinds of water qualities and wide in application occasions; no fixture device is needed and the convenience is effectively improved.