The invention relates to a method for purifying a super great amount of water, which comprises the following steps: step I, the target water is selected; step II, the reference 
water depth(D1) is determined; when the actual depth of the target water is 10-50 meters, the reference 
water depth is the actual depth; when the target 
water depth is more than 50 meters, the reference water depth(D1) is 50 meters; step III, a purifying device, an 
air water-raising tunnel, is arranged in the target waters, and the tunnel body length (L1) of the 
air water-raising tunnel is 30 percent-50 percent of the reference water depth(D1) of the target water; the submerged depth of the tunnel mouth (D2) of the 
air water-raising tunnel is 40 percent-60 percent of the tunnel body length (D1); step IV, the air is input into a pressure chamber of the air water-raising tunnel and the air pressure(P1) of an 
air compressor is 150 percent-200 percent of 
water pressure in the pressure chamber. The invention can realize 
convection of an upper 
water layer and a lower 
water layer as well as realize the whole circulation, thus effectively facilitating dissolved 
oxygen quantity in the whole waters, damaging suspension state of 
algae and inhibiting the growth of the 
algae so as to purify the water.