General Secretary Xi Jinping pointed out that "Internet civilization is an important part of social civilization under the new situation and an important field for building a strong Internet country." Currently, the Internet has deeply integrated into all aspects of people's lives, gradually becoming the main channel for information dissemination, a new space for cultural prosperity, and a new engine for economic development. In this process, the importance of online civilization has become increasingly prominent. It not only concerns the shaping of personal qualities and values, but also affects the level of civilization and harmonious development of the entire society. As a channel for young people to express themselves online, bullet screen interaction also needs to adhere to the bottom line of civilization. Barrage is a type of comment text or symbol that scrolls in real-time on video frames in a floating form, and has become a unique form of online interaction due to its immediacy and fun. Among the youth group, bullet screen interaction has a wide range of usage scenarios, including emotional resonance during TV shows, humorous interaction in variety shows, and knowledge exchange in learning videos. Young people convey diverse emotional attitudes through professional insights, personality expressions, and trendy symbols. This form not only provides an effective channel for young people to express their opinions, allowing individual viewpoints to quickly integrate into group discussions, but also generates new cultural symbols through ideological collisions, becoming an important carrier for social interaction and value shaping among young people. It is worth noting that the barrage is also filled with many false, hollow, even extreme or inappropriate remarks. From fragmented rumors taken out of context and meaningless empty water, to extreme statements that vent emotions and vulgar jokes that break the bottom line, similar negative expressions often appear. These contents not only disrupt the normal order of information dissemination, but also mislead the value of young people whose judgment is still developing, causing them to unconsciously blur the boundaries of expression. Especially when vulgar speech and extreme views are spread frequently through bullet comments, it not only destroys the civilized background of cyberspace, but also may touch the dual red lines of law and morality, and have a negative impact on the youth group. Building a solid foundation for online civilization and safeguarding a clear cyberspace requires young people to actively practice civilized norms in barrage interactions, internalizing the self-discipline principles of rational expression and compliance with morality and law into conscious action. Although the barrage is short, it is still a part of the online public space. The newly revised Regulations on the Management of Internet Posting Review Service issued by the National Cyberspace Office clearly points out that the pop-up screen is part of the post review, and it is included in the scope of standardized management. Young people should consciously abide by barrage etiquette, speak in a civilized and rational manner during barrage interactions. Sending bullet comments should take "authenticity" as the basic criterion and not send unverified knowledge or uncertain answers in a positive tone. Promptly point out any erroneous knowledge discovered and label the correct answers or links, making each frame an interactive knowledge node, transforming the barrage from a fragmented comment area to a verifiable and reliable flowing knowledge base, allowing real information to continue to add value in interaction, and injecting rigorous knowledge dissemination genes into the digital space. Youth can use bullet comments as a medium to make positive values the spiritual foundation of online communication. Clear the cognitive fog with rational thinking, calibrate the boundaries of discourse with civilized expression, and make every barrage a youthful expression of the spirit of the times. In information exchange, using socialist core values as the coordinate anchor point, fragmented barrage texts are condensed into a bond of value consensus, and a youth spirit map is constructed through collective screen brushing, allowing the spirit of the times to touch the daily lives of young people and converge into a value flood of upward goodness in cyberspace, resonating with the spirit of the times. (Xinhua News Agency) Author: Han Miao (Researcher at the Training and Training Center for Ideological and Political Work Teams in Higher Education Institutions of the Ministry of Education [Nanjing Normal University])