Abstract: A certain nuclear power plant was originally equipped with GE's SR series plug-in microcomputer integrated protection devices. After nearly 20 years of operation, the production of this series of equipment had been discontinued. Under the trend of localization, the nuclear power plant replaced the original GE products with PCS-9625H front-plug-in microcomputer integrated protection devices. Taking the renovation of the station service integrated protection devices in this nuclear power plant as an example, this text analyzes the localization process and its effects from the aspects of specifications, design, and practice.