This study explores how Chinese college students use multimodal practices to construct national images through short videos, within the context of national image-building and cultural soft power competition. Using visual grammar and systemic functional grammar frameworks, a multimodal analysis was conducted on 20 gold-medal-winning entries from the 2024 “FLTRP·ETIC Cup ‘Understanding Contemporary China’ Short Video Contest”. The findings reveal how students use visual language and subtitles to shape the image of Digital China. Through the narrative structure of empowering technology, preserving culture, and passing the torch between generations, students incorporate national technological strength, cultural identity, and individual responsibility. This process creates a mechanism of technological embodiment, emotional normalization, and identity-driven storytelling. By moving beyond traditional grand narratives, the study confirms the theoretical effectiveness of multimodal discourse in identity construction and presents a new perspective on folk discourse from Chinese college students. It also provides insights for enhancing the effectiveness of national narrative communication.