Separated storage tank for replacing oil and water under water

The utility model relates to a novel storage tank for replacing oil and water underwater, which is an isolation type storage tank for replacing oil and water underwater, which is composed of a storage tank main body, an oil and water separating cloth, a water inlet, a water outlet, an oil filling pipe, an oil outlet pipe, an inflating pipe and an oily sewage flexible suction pipe, wherein the edge of the oil and water separating cloth is fixed to the middle of the side wall of the storage tank main body, and the water inlet and the water outlet are arranged below the oil and water separating cloth at the side wall of the storage tank main body. The oil filling pipe, the oil outlet pipe, the inflating pipe and the oily sewage flexible suction pipe are arranged above the oil and water separating cloth on the storage tank main body. The utility model can avoid contamination caused by oil and water replacement, and is suitable for the underwater storage of crude oil with water or without water.