A multifunctional suspension type river ecology enclosure experiment device comprises an aluminum alloy framework, floating balls fixedly arranged on the aluminum alloy framework, a supporting net, an enclosure bag, sun shading cloth, a mixing system and a water circulating system. The aluminum alloy framework is formed by a plurality of aluminum alloy rods which are connected in a welding mode to form a grid type rectangular framework structure. The supporting net is formed by high strength ropes which are woven in a stagger mode to form a net shape, the top of the supporting net is open and is bolted on the aluminum alloy framework, and the bottom of the supporting net is sealed. The enclosure bag is arranged in the supporting net in a pocketing mode, the top of the enclosure bag is open and is fixedly arranged on the aluminum alloy framework, the bottom of the enclosure bag is connected with a phycophyta filtering screen, the side wall of the enclosure bag is connected to the supporting net, and the enclosure bag is light pervious and waterproof. Stone weights are connected with the bottom of the supporting net through ropes. Pulling ropes and mooring ropes are connected on the aluminum alloy framework, buckling rings and the pulling ropes are connected and fixedly arranged on timber piles on a river bank. The enclosure experiment device is fixedly arranged on a river bed by rivets through the mooring ropes. The multifunctional suspension type river ecology enclosure experiment device is easy to disassemble and assemble, capable of enabling experimental observation to be carried out in any water area of a river and high in flexibility and practicability.