The invention discloses an intelligent nitrogen sealed water tank provided with a flexible floating roof device. The intelligent nitrogen sealed water tank comprises a control center, a display module, a nitrogen tank, a first wireless communication module, a second wireless communication module and a nitrogen sealed water tank body. The gas outlet end of the nitrogen tank communicates with the nitrogen sealed water tank body through a gas inlet pipe. The gas inlet pipe communicates with a gas flowmeter and a nitrogen sealed valve, and the top of the nitrogen sealed water tank body communicates with a first exhaust pipe and a second exhaust pipe. The first exhaust pipe communicates with a breather valve and a first exhaust flowmeter, and the second exhaust pipe communicates with a pressurerelease valve and a second exhaust flowmeter. A pressure sensor is embedded to the top of the nitrogen sealed water tank body. The bottom end of the pressure sensor extends into the nitrogen sealed water tank body. The intelligent nitrogen sealed water tank provided with the flexible floating roof device has the beneficial effects of being capable of monitoring the nitrogen content, ultrapure water content, nitrogen pressure and the like in the nitrogen sealed water tank body, and the problem that the fault of the nitrogen sealed water tank body cannot be found in time is solved.