Method for purifying circulating water of SCAL type indirect air cooling unit

The invention discloses a method for purifying circulating water of an SCAL type indirect air cooling unit, and the specific technical scheme is as follows: the method for purifying the circulating water of the SCAL type indirect air cooling unit comprises the following steps: enabling the circulating water of the SCAL type indirect air cooling unit to pass through a bypass flow treatment system to enable the total water quality of the circulating water to be qualified, wherein the bypass flow treatment system is formed by sequentially connecting a booster pump and a bypass thereof, a plate cooler and a bypass thereof, a large-flow filter element filter, a cation exchanger and an anion exchanger and a bypass thereof, and an EDI and a bypass thereof in series. Whether each part is put intooperation or bypassed is selected according to the pressure difference between a water taking point and a water returning point, the temperature of the water taking point, the conductivity of the water taking point and the co