Abstract: In order to comprehensively promote the construction of water sector calculation data, algorithm and calculation capacity, build a digital twin basin and improve the hydrological information monitoring capacity, the current advanced non-contact online flow measurement system is used to carry out comparative test between the measured flow and the flow of the same period monitored by the system online through the flow measurement at Jiegang hydrological station and the conventional cableway current meter The error and correlation between flow and other parameters are compared and analyzed. The results show that the flow measurement system has good correlation between medium and high water above the water level of the basic water gauge section is above 819.50, and the error is within the allowable range.