At present, portable ultrasonic flow meter is used for the cooling water flow meter of circulating water cooler in the 220 kt/a ethylene plant in Dushanzi. Because it has been used for many years, the probe is aged and the measurement accuracy and sensitivity are poor. Comparing the monitoring data of the portable ultrasonic meter with the measurement data displayed by DCS in May 2023, it is found that the monitoring results of the portable ultrasonic meter are about 66.7％ higher than the actual values. As a result, the circulating water consumption of the circulating water cooler of the plant increases by 9.32％ compared with the design value, which seriously affects the operation energy consumption of the plant. In order to scientifically control the circulating water consumption, the operation data of the circulating water heat exchanger under the current production conditions are collected, including material components, material inlet and outlet temperature/pressure, circulating water inlet and outlet temperature/pressure, etc. Aspen Hysys software is used to simulate the circulating water consumption of each water cooler, find out the deviation points, optimize the control, and achieve the purpose of improving the quality and efficiency.