Abstract: A high-performance seafloor flexible oil storage system, solving the existing problems of high storage cost and difficult maintenance of crude oil in offshore oilfields, comprises, sequentially connected, an oil-water separator, a pressure pump, and an input riser extending downward below the sealevel; and a pipeline and multiple flexible oil storage tanks having the same structure with each communicated therewith through a control valve are arranged below the sealevel. One end of the pipeline is communicated with the input riser through a blocking valve and an input valve, and the other end further sequentially connected with an outlet booster pump, an output valve, and an output riser extending upwards above the sealevel and connected to a tanker through a cooler and an output pump. The flexible oil storage tank has a concrete counterweight connected thereunder for fixing it to a seabed. The system has simple structure, convenient maintenance and good practicability.