This paper discusses the reform and innovation of Civics teaching in the course of "Operating System". Operating system is a core professional course for computer science majors, and its theoretical and practical nature is strong and abstract, which makes most students not interested in learning the course. It proposes to apply the online and offline hybrid teaching mode in operating system, through network sharing, updating teaching contents, reforming teaching methods, proposing diversified assessment standards, and examining students' knowledge, ability and quality achievement in multiple dimensions. The teaching practice shows that the introduction of the Civics element in the course and the adoption of the online and offline hybrid teaching mode can greatly enhance students' interest in learning and cultivate their patriotism and responsibility. The reform of the OS course has effectively improved the depth and innovation of the course, enhanced the teaching quality and students' comprehensive quality, and achieved better teaching effect and evaluation, which hopefully can provide reference for other professional courses to carry out the teaching of Civics.