Abstract: In the context of the 15th National Games of the People's Republic of China co-hosted by the Guangdong-Hong Kong-Macao Greater Bay Area, this study examines Douyin and YouTube, two social media platforms with distinct operational mechanisms, and collects relevant video data from 2021 to 2025 to analyze the cross-platform communication of the Chinese sports spirit from the dimensions of communicators, content, and dissemination. The findings indicate that, at the communicator level, high-impact accounts significantly enhance communication effectiveness, with Douyin demonstrating a more pronounced social diffusion effect. At the content level, the representation of the Chinese sports spirit in specific sporting contexts is more likely to generate interaction and discussion, whereas content orientation and richness alone exert limited influence. At the dissemination level, Douyin is characterized by short-term, concentrated traffic surges, whereas YouTube exhibits a pattern of gradual accumulation; platform algorithms and interaction mechanisms create notable differences in dissemination pathways and visibility. Accordingly, it is necessary to establish a multi-stakeholder collaborative communication system, bolster authoritative content provision and cross-border alignment, convey the core values of the Chinese sports spirit in various sporting contexts, and optimize interaction design and dissemination pathways tailored to different platforms, thereby providing a practical reference for the precise integration and cross-platform communication of the Chinese sports spirit in future sporting events.