Pure water supplying system capable of controlling oxygen dissolving content and degassing method thereof

The invention relates to a purified water supply system of controlling oxygen dissolved quantity and a degassing method thereof. A degassing process is carried out in a capacity space which is injected with purified water through an air exhaust device, the oxygen dissolved in the purified water is separated out, thus reducing the dissolved oxygen quantity of the purified water; meanwhile, a detection signal is sent to a controller by detecting the dissolved oxygen quantity of the purified water through a detection device.; the operating power of the degassing device is adjusted according to the detection signal, and the dissolved oxygen quantity of the purified water is controlled, thereby maintaining the dissolved oxygen quantity in a certain range.