The utility model discloses an ecological floating island for purifying water in a deep water area. The ecological floating island comprises a frame system, a microcirculation system and a fixing system arranged around the frame system, the frame system comprises a peripheral floating frame, a first floating platform and a second floating platform, wherein the first floating platform and the second floating platform are arranged in a middle groove of the peripheral floating frame. And the microcirculation system longitudinally penetrates through the middle position of the frame system, so thata circulating reoxygenation vortex is formed at the lower part of the outer side of the circumference of the frame system. Through the arranged frame system, emergent aquatic plants, floating-leavedplants, submerged plants, artificial waterweeds and the like can be planted and carried at the same time, a plant community suitable for deep water area water quality purification is constructed, three-dimensional purification of a deep water area from top to bottom is achieved, and a good deep water area water quality purification effect is achieved.