Abstract: Equipment Cooling Water System（RRI） is an important auxiliary system of nuclear power plants, and its users cover the fields of nuclear island and the periphery of nuclear power plant facilities systems（BOP）system. It must be ensured that the Equipment Cooling Water System can operate stably under normal operation condition and various accident conditions. Hence, equipment performance and logic functions of RRI must be verified one by one. This paper focuses on fluctuating tank test, motor pump test, flux adjustment test, and automatic switch test of different serials, analyzes and judges the problems occurred in the tests, and discusses the flux distribution method, hole-digging calculation method and the influence on the flux by the reverse installation of flow orifices, and the way to solve these problems.