Abstract: With the development of industrial digitalization, networking and intelligence, the security of I＆C systems of nuclear power plants can’t be guaranteed using the traditional method based on physical isolation. Cyber attacks on I＆Cs may cause the production process interruption and even nuclear safety incidents, thus attracting great attention of interested countries and organizations. In 2020, IEC issued IEC 63096 which provides specific guidance based on the security degree and life cycle aiming to help all parties involved in I＆C implement security controls to prevent, detect and correct cyber attacks. Accordingly, China has been implementing classified protection system of cyber security for all industries including the nuclear power sector. This paper makes introduction respectively on the IEC 63096 and national classified protection standards, focuses on the analysis of coordination about the security degree and security controls between the two, so as to help NPPs in the deployment of security controls with relative low time costs and investment costs.